cp's OEIS Frontend

This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.

Showing 1-10 of 10 results.

A183204 Central terms of triangle A181544.

Original entry on oeis.org

1, 4, 48, 760, 13840, 273504, 5703096, 123519792, 2751843600, 62659854400, 1451780950048, 34116354472512, 811208174862904, 19481055861877120, 471822589361293680, 11511531876280913760, 282665135367572129040
Offset: 0

Views

Author

Paul D. Hanna, Dec 30 2010

Keywords

Comments

The g.f. for row n of triangle A181544 is (1-x)^(3n+1)*Sum_{k>=0}C(n+k-1,k)^3*x^k.
This sequence is s_7 in Cooper's paper. - Jason Kimberley, Nov 06 2012
Diagonal of the rational function R(x,y,z,w) = 1/(1 - (w*x*y + w*x*z + w*y*z + x*y + x*z + y + z)). - Gheorghe Coserea, Jul 14 2016
This is one of the Apery-like sequences - see Cross-references. - Hugo Pfoertner, Aug 06 2017
Every prime eventually divides some term of this sequence. - Amita Malik, Aug 20 2017

Examples

			Triangle A181544 begins:
(1);
1, (4), 1;
1, 20, (48), 20, 1;
1, 54, 405, (760), 405, 54, 1;
1, 112, 1828, 8464, (13840), 8464, 1828, 112, 1; ...
		

Crossrefs

Related to diagonal of rational functions: A268545-A268555.
The Apéry-like numbers [or Apéry-like sequences, Apery-like numbers, Apery-like sequences] include A000172, A000984, A002893, A002895, A005258, A005259, A005260, A006077, A036917, A063007, A081085, A093388, A125143 (apart from signs), A143003, A143007, A143413, A143414, A143415, A143583, A183204, A214262, A219692,A226535, A227216, A227454, A229111 (apart from signs), A260667, A260832, A262177, A264541, A264542, A279619, A290575, A290576. (The term "Apery-like" is not well-defined.)

Programs

  • Magma
    P:=PolynomialRing(Integers()); C:=Binomial;
    A183204:=func; // or directly:
    A183204:=func;
    [A183204(n):n in[0..16]]; // Jason Kimberley, Oct 29 2012
  • Mathematica
    Table[Sum[Binomial[n,j]^2 * Binomial[2*j,n] * Binomial[j+n,j],{j,0,n}],{n,0,20}] (* Vaclav Kotesovec, Apr 05 2015 *)
  • PARI
    {a(n)=polcoeff((1-x)^(3*n+1)*sum(j=0, 2*n, binomial(n+j, j)^3*x^j), n)}
    

Formula

a(n) = [x^n] (1-x)^(3n+1) * Sum_{k>=0} C(n+k-1,k)^3*x^k.
a(n) = Sum_{j = 0..n} C(n,j)^2 * C(2*j,n) * C(j+n,j). [Formula of Wadim Zudilin provided by Jason Kimberley, Nov 06 2012]
1/Pi = sqrt(7) Sum_{n>=0} (-1)^n a(n) (11895n + 1286)/22^(3n+3). [Cooper, equation (41)] - Jason Kimberley, Nov 06 2012
G.f.: sqrt((1-13*x+(1-26*x-27*x^2)^(1/2))/(1-21*x+8*x^2+(1-8*x)*(1-26*x-27*x^2)^(1/2)))*hypergeom([1/12,5/12],[1],13824*x^7/(1-21*x+8*x^2+(1-8*x)*(1-26*x-27*x^2)^(1/2))^3)^2. - Mark van Hoeij, May 07 2013
a(n) ~ 3^(3*n+3/2) / (4 * (Pi*n)^(3/2)). - Vaclav Kotesovec, Apr 05 2015
G.f. A(x) satisfies 1/(1+4*x)^2 * A( x/(1+4*x)^3 ) = 1/(1+2*x)^2 * A( x^2/(1+2*x)^3 ) [see Cooper, Guillera, Straub, Zudilin]. - Joerg Arndt, Apr 08 2016
a(n) = (-1)^n*binomial(3n+1,n)* 4F3({-n,n+1,n+1,n+1};{1,1,2(n+1)}; 1). - M. Lawrence Glasser, May 15 2016
Conjecture D-finite with recurrence: n^3*a(n) - (2*n-1)*(13*n^2-13*n+4)*a(n-1) - 3*(n-1)*(3*n-4)*(3*n-2)*a(n-2) = 0. - R. J. Mathar, May 15 2016
0 = (-x^2+26*x^3+27*x^4)*y''' + (-3*x+117*x^2+162*x^3)*y'' + (-1+86*x+186*x^2)*y' + (4+24*x)*y, where y is g.f. - Gheorghe Coserea, Jul 14 2016
From Jeremy Tan, Mar 14 2024: (Start)
The conjectured D-finite recurrence can be proved by Zeilberger's algorithm.
a(n) = Sum_{k=0..n} binomial(n,k)^2 * binomial(n+k,n) * binomial(2*n-k,n) = [(w*x*y*z)^n] ((w+y)*(x+z)*(y+z)*(w+x+y+z))^n. (End)
a(n) = Sum_{0 <= j, k <= n} binomial(n, k)^2 * binomial(n, j)^2 * binomial(k+j, n) = Sum_{k = 0..n} binomial(n, k)^2 * A108625(n, k). - Peter Bala, Jul 08 2024
From Peter Bala, Sep 18 2024: (Start)
a(n) = Sum_{k = 0..n} (-1)^(n-k)*binomial(n+k, k)^3*binomial(3*n+1, n-k). Cf A245086.
a(n) = Sum_{k = 0..n} (-1)^(n+k)*binomial(n, k)*A143007(n, k) (verified using the MulZeil procedure in Doron Zeilberger's MultiZeilberger package). (End)

A357407 a(n) = coefficient of x^n, n >= 0, in A(x) = exp( Sum_{n>=1} A183204(n)*x^n/n ), where A183204 equals the central terms of triangle A181544.

Original entry on oeis.org

1, 4, 32, 360, 4964, 78064, 1344020, 24708928, 477282794, 9580852360, 198322047840, 4209371498256, 91221481924426, 2011834246746792, 45039165331725264, 1021419638492387856, 23426910170090512779, 542666070296546760492, 12681393784980089971368
Offset: 0

Views

Author

Paul D. Hanna, Oct 19 2022

Keywords

Comments

A183204(n) = Sum_{k=floor(n/2)..n} C(n,k)^2 * C(2*k,n) * C(n+k,k).
A183204(n) equals the coefficient of x^n in (1-x)^(3*n+1) * Sum_{k>=0} binomial(n+k-1,k)^3 * x^k, which is the central term of row n of triangle A181544.

Examples

			G.f.: A(x) = 1 + 4*x + 32*x^2 + 360*x^3 + 4964*x^4 + 78064*x^5 + 1344020*x^6 + 24708928*x^7 + 477282794*x^8 + 9580852360*x^9 + 198322047840*x^10 + ...
where
log(A(x)) = 4*x + 48*x^2/2 + 760*x^3/3 + 13840*x^4/4 + 273504*x^5/5 + 5703096*x^6/6 + 123519792*x^7/7 + 2751843600*x^8/8 + 62659854400*x^9/9 + ... + A183204(n)*x^n/n + ...
		

Crossrefs

Programs

  • PARI
    {A183204(n) = sum(k=n\2,n, binomial(n,k)^2 * binomial(2*k,n) * binomial(n+k,k) )}
    {a(n) = polcoeff( exp( sum(m=1,n, A183204(m)*x^m/m ) + x*O(x^n) ),n)}
    for(n=0,20,print1(a(n),", "))

Formula

a(n) ~ c * 3^(3*n) / n^(5/2), where c = 0.289447274610263555814082139782101227837126089347468995035938970190651243... - Vaclav Kotesovec, Mar 14 2023

A293286 a(n) = A181544(2n, 2n-1).

Original entry on oeis.org

20, 8464, 4050864, 2116980800, 1173644492800, 678353946298560, 404352269157205152, 246796318508780847360, 153477802845690943118400, 96903346351876187722368000, 61954834924471706682462940800, 40029904663914104968204952365824, 26096917229103772343967114415006304
Offset: 1

Views

Author

Eric M. Schmidt, Oct 04 2017

Keywords

Programs

  • Mathematica
    t[n_, k_] := SeriesCoefficient[Sum[Binomial[n + j, j]^3 x^j, {j, 0, n + k}] (1 - x)^(3n + 1), {x, 0, k}];
    a[n_] := t[2n, 2n - 1];
    Array[a, 13] (* Jean-François Alcover, Feb 14 2019 *)
  • Sage
    def a(n) :
        R. = QQ[]; p = 2*n; q = 2*n-1
        return ((1-x)^(3*p+1) * sum(binomial(p+r,r)^3 * x^r for r in [0..p+q]))[q]

A181543 Triangle of cubed binomial coefficients, T(n,k) = C(n,k)^3, read by rows.

Original entry on oeis.org

1, 1, 1, 1, 8, 1, 1, 27, 27, 1, 1, 64, 216, 64, 1, 1, 125, 1000, 1000, 125, 1, 1, 216, 3375, 8000, 3375, 216, 1, 1, 343, 9261, 42875, 42875, 9261, 343, 1, 1, 512, 21952, 175616, 343000, 175616, 21952, 512, 1, 1, 729, 46656, 592704, 2000376, 2000376, 592704, 46656, 729, 1
Offset: 0

Views

Author

Paul D. Hanna, Oct 30 2010

Keywords

Comments

Diagonal of rational function R(x,y,z,t) = 1/(1 + y + z + x*y + y*z + t*x*z + (t+1)*x*y*z) with respect to x, y, z, i.e., T(n,k) = [(xyz)^n*t^k] R(x,y,z,t). - Gheorghe Coserea, Jul 01 2018

Examples

			Triangle begins:
  1;
  1,   1;
  1,   8,     1;
  1,  27,    27,      1;
  1,  64,   216,     64,       1;
  1, 125,  1000,   1000,     125,       1;
  1, 216,  3375,   8000,    3375,     216,      1;
  1, 343,  9261,  42875,   42875,    9261,    343,     1;
  1, 512, 21952, 175616,  343000,  175616,  21952,   512,   1;
  1, 729, 46656, 592704, 2000376, 2000376, 592704, 46656, 729, 1;
  ...
		

Crossrefs

Cf. A000172 (row sums), A181545 (antidiagonal sums), A002897, A181544, A248658.
Variants: A008459, A007318.

Programs

  • Maple
    T:= (n, k)-> binomial(n, k)^3:
    seq(seq(T(n, k), k=0..n), n=0..10);  # Alois P. Heinz, Jan 06 2021
  • Mathematica
    Flatten[Table[Binomial[n,k]^3,{n,0,10},{k,0,n}]] (* Harvey P. Dale, May 23 2011 *)
  • PARI
    T(n,k)=binomial(n,k)^3
    for(n=0,10,for(k=0,n,print1(T(n,k),", "));print())
    
  • PARI
    T(n,k)=polcoeff(polcoeff(sum(m=0,n,(3*m)!/m!^3*x^(2*m)*y^m/(1-x-x*y+x*O(x^n))^(3*m+1)),n,x),k,y)
    for(n=0,10,for(k=0,n,print1(T(n,k),", "));print()) \\ Paul D. Hanna, Nov 04 2010
    
  • PARI
    diag(expr, N=22, var=variables(expr)) = {
      my(a = vector(N));
      for (k = 1, #var, expr = taylor(expr, var[#var - k + 1], N));
      for (n = 1, N, a[n] = expr;
        for (k = 1, #var, a[n] = polcoeff(a[n], n-1)));
      return(a);
    };
    x='x; y='y; z='z; t='t;
    concat(apply(Vec, diag(1/(1 + y + z + x*y + y*z + t*x*z + (t+1)*x*y*z), 10, [x, y, z]))) \\ Gheorghe Coserea, Jul 01 2018

Formula

Row sums equal A000172, the Franel numbers.
Central terms are A002897(n) = C(2n,n)^3.
Antidiagonal sums equal A181545;
The g.f. of the antidiagonal sums is Sum_{n>=0} (3n)!/(n!)^3 * x^(3n)/(1-x-x^2)^(3n+1).
G.f. for column k: [Sum_{j=0..2k} A181544(k,j)*x^j]/(1-x)^(3k+1), where the row sums of A181544 equals De Bruijn's s(3,n) = (3n)!/(n!)^3.
G.f.: A(x,y) = Sum_{n>=0} (3n)!/n!^3 * x^(2n)*y^n/(1-x-x*y)^(3n+1). - Paul D. Hanna, Nov 04 2010

A236463 Irregular triangle read by rows: T(n,k) = Sum_{i=0..k} (-1)^i * binomial(4*n+1,i) * binomial(k+4-i,4)^n, 0 <= k <= 4*(n-1).

Original entry on oeis.org

1, 1, 16, 36, 16, 1, 1, 112, 1828, 8464, 13840, 8464, 1828, 112, 1, 1, 608, 40136, 724320, 4961755, 15018688, 21571984, 15018688, 4961755, 724320, 40136, 608, 1, 1, 3104, 693960, 37229920, 733059110, 6501577152, 29066972368, 69830127680, 93200908410, 69830127680
Offset: 1

Views

Author

Yahia Kahloune, Feb 01 2014

Keywords

Comments

In general, define b(k,e,p) = Sum_{i=0..k} (-1)^i*binomial(e*p+1,i)*binomial(k+e-i,e)^p. Then T(n,k) = b(k,4,n).
Using these coefficients we can obtain formulas for binomial(n,e)^p and for Sum_{i=1..n} binomial(e-1+i,e)^p.
In particular:
binomial(n, e)^p = Sum_{k=0..e*(p-1)} b(k,e,p) * binomial(n+k, e*p).
Sum_{i=1..n} binomial(e-1+i, e)^p = Sum_{k=0..e*(p-1)} b(k,e,p) * binomial(n+e+k, e*p+1).
T(n,k) is the number of permutations of 4 indistinguishable copies of 1..n with exactly k descents. A descent is a pair of adjacent elements with the second element less than the first. - Andrew Howroyd, May 08 2020

Examples

			T(n,0) = 1;
T(n,1) = 5^n - (4*n+1);
T(n,2) = 15^n - (4*n+1)*5^n + C(4*n+1,2);
T(n,3) = 35^n - (4*n+1)*15^n + C(4*n+1,2)*5^n - C(4*n+1,3);
T(n,4) = 70^n - (4*n+1)*35^n + C(4*n+1,2)*15^n - C(4*n+1,3)*5^n + C(4*n+1,4).
Triangle T(n,k) begins:
1,
1, 16, 36, 16, 1;
1, 112, 1828, 8464, 13840, 8464, 1828, 112, 1;
1, 608, 40136, 724320, 4961755, 15018688, 21571984, 15018688, 4961755, 724320, 40136, 608, 1;
1, 3104, 693960, 37229920, 733059110, 6501577152, 29066972368, 69830127680, 93200908410, 69830127680, 29066972368, 6501577152, 733059110, 37229920, 693960, 3104, 1;
1, 15600, 11000300, 1558185200, 75073622025, 1585757994496, 16938467955200, 99825129369600, 342907451401150, 710228619472800, 903546399077256, 710228619472800, 342907451401150, 99825129369600, 16938467955200, 1585757994496, 75073622025, 1558185200, 11000300, 15600, 1;
  ...
Example:
Sum_{i=1..n} C(3+i,4)^3 = C(n+4,13) + 112*C(n+5,13) + 1828*C(n+6,13) + 8464*C(n+7,13) + 13840*C(n+8,13) + 8464*C(n+9,13) + 1828*C(n+10,13) + 112*C(n+11,13) + C(+12,13).
C(n,4)^3 = C(n,12) + 112*C(n+1,12) + 1828*C(n+2,12) + 8464*C(n+3,12) + 13840*C(n+4,12) + 8464*C(n+5,12) + 1828*C(n+6,12) + 112*C(n+7,12) + C(n+8,12).
		

Crossrefs

Row sums are A014608.
Similar triangles for e=1..6: A173018 (or A008292), A154283, A174266, this sequence, A237202, A237252.
Sum_{i=1..n} binomial(3+i,4)^p for p=2..3 gives: A086023, A086024.

Programs

  • Mathematica
    b[k_, 4, p_] := Sum[(-1)^i*Binomial[4*p+1, i]*Binomial[k-i, 4]^p /. k -> 4+i, {i, 0, k-4}]; row[p_] := Table[b[k, 4, p], {k, 4, 4*p}]; Table[row[p], {p, 1, 6}] // Flatten (* Jean-François Alcover, Feb 05 2014 *)
  • PARI
    T(n,k)={sum(i=0, k, (-1)^i*binomial(4*n+1, i)*binomial(k+4-i, 4)^n)} \\ Andrew Howroyd, May 08 2020

Formula

Sum_{i=1..n} binomial(3+i,4)^p = Sum{k=0..4*(p-1)} T(p,k) * binomial(n+4+k, 4*p+1).
binomial(n,4)^p = Sum_{k=0..4*(p-1)} T(p,k) * binomial(n+k, 4*p).

Extensions

a(36) corrected by Vincenzo Librandi, Feb 14 2014
Edited by Andrew Howroyd, May 08 2020

A126086 Number of paths from (0,0,0) to (n,n,n) such that at each step (i) at least one coordinate increases, (ii) no coordinate decreases, (iii) no coordinate increases by more than 1 and (iv) all coordinates are integers.

Original entry on oeis.org

1, 13, 409, 16081, 699121, 32193253, 1538743249, 75494983297, 3776339263873, 191731486403293, 9850349744182729, 510958871182549297, 26716694098174738321, 1406361374518034383189, 74456543501901550262689, 3961518532003397434536961, 211689479080817606497324033
Offset: 0

Views

Author

Nick Hobson, Mar 03 2007

Keywords

Comments

Also, the number of alignments for 3 sequences of length n each (Slowinski 1998).
This is a 3-dimensional generalization of A001850.

Examples

			Illustrating a(1) = 13:
000 -> 001 -> 011 -> 111
000 -> 001 -> 101 -> 111
000 -> 001 -> 111
000 -> 010 -> 011 -> 111
000 -> 010 -> 110 -> 111
000 -> 010 -> 111
000 -> 100 -> 101 -> 111
000 -> 100 -> 110 -> 111
000 -> 100 -> 111
000 -> 011 -> 111
000 -> 101 -> 111
000 -> 110 -> 111
000 -> 111
		

Crossrefs

Column k=3 of A262809.

Programs

  • Maple
    f := proc(n) local i,k; add(add((-1)^k*binomial(k,i)*(-1)^i*binomial(i,n)^3,i=n..k),k=n..3*n) end: # Brendan McKay, Mar 03 2007
    seq(sum(binomial(k,n)^3/2^(k+1),k=n..infinity),n=0..10); # Vladeta Jovovic, Mar 01 2008
  • Mathematica
    m = 14; se = Series[1/(1 - x - y - z - x*y - x*z - y*z - x*y*z), {x, 0, m}, {y, 0, m}, {z, 0, m}]; a[n_] := Coefficient[se, (x*y*z)^n]; a[0] = 1; Table[a[n], {n, 0, m}] (* Jean-François Alcover, Sep 27 2011, after Max Alekseyev *)
    Table[Sum[Sum[(-1)^k*Binomial[k,i]*(-1)^i*Binomial[i,n]^3,{i,n,k}],{k,n,3*n}],{n,0,20}] (* Vaclav Kotesovec, Mar 15 2014, after Brendan McKay *)
  • Python
    # Naive version - see link for better version.
    def f(a, b):
        if a == 0 or b == 0:
            return 1
        return f(a, b - 1) + f(a - 1, b) + f(a - 1, b - 1)
    def g(a, b, c):
        if a == 0:
            return f(b, c)
        if b == 0:
            return f(c, a)
        if c == 0:
            return f(a, b)
        return (
            g(a, b, c - 1)
            + g(a, b - 1, c)
            + g(a - 1, b, c)
            + g(a, b - 1, c - 1)
            + g(a - 1, b, c - 1)
            + g(a - 1, b - 1, c)
            + g(a - 1, b - 1, c - 1)
        )
    for n in range(6):
        print(g(n, n, n), end=", ")

Formula

a(n) can be computed as the coefficient of (xyz)^n in the expansion of 1 / (1-x-y-z-xy-xz-yz-xyz). Also, - 2*(n+1)^2 * a(n) + (n+1)*(5n+8) * a(n+1) - 3*(37*n^2 + 146*n + 139) * a(n+2) - (55*n^2 + 389*n + 685) * a(n+3) + (n+4)^2 * a(n+4) = 0. - Max Alekseyev, Mar 03 2007
For Brendan McKay's explicit formula see the Maple code.
From Dan Dima, Mar 03 2007: (Start)
I found a very simple (although infinite) sum for the number of paths from (0,0,...,0) to (a(1),a(2),...,a(k)) using "nonzero" (2^k-1) steps of the form (x(1),x(2),...,x(k)) where x(i) is in {0,1} for 1<=i<=k, k-dimensions.
f(a(1),a(2),...,a(k)) = Sum( (C(n;a(1)) * C(n;a(2)) * ... C(n;a(k))) / 2^{n+1}, {n, max(a(1),a(2),...,a(k)), infinity}), Sum( (C(n;a(1)) * C(n;a(2)) * ... C(n;a(k))) / 2^{n+1}, {n, 0, infinity}), C(n;a)=n!/a!(n-a)! & we assumed C(n;a)=0 if n
Also f(a(1),a(2),...,a(k)) can be computed as the coefficient of x(1)^a(1)...x(k)^a(k) in the expansion: 1/2 * 1/(1 - (1+x(1))*...*(1+x(k))/2). (End)
From David W. Cantrell (DWCantrell(AT)sigmaxi.net), Mar 03 2007: (Start)
Using pseudo-Mathematica-style notation, f(a(1),a(2),...,a(k)) is 2^(-1 - a(1)) (a(1)!)^(k-1)/(a(2)! a(3)! ... a(k)!) * HypergeometricPFQRegularized[{1, 1 + a(1), 1 + a(1),..., 1 + a(1)}, {1, 1 + a(1) - a(2), 1 + a(1) - a(3),..., 1 + a(1) - a(k)}, 1/2]
Although it should be obvious from the above that there are k denominatorial parameters, it is not obvious that there are to be (k+1) numeratorial parameters [one of which is 1 and the other k of them are 1 + a(1)]. In other words, we have P = k + 1 and Q = k.
For information about HypergeometricPFQRegularized, see http://functions.wolfram.com/HypergeometricFunctions/HypergeometricPFQRegularized/ . (End)
G.f.: hypergeom([1/3,2/3],[1], 54*x/(1-x)^3)/(1-x). - Mark van Hoeij, Mar 25 2012.
Recurrence (of order 3): n^2*(3*n-4)*a(n) = (3*n-2)*(57*n^2 - 95*n + 25)*a(n-1) - (9*n^3 - 30*n^2 + 29*n - 6)*a(n-2) + (n-2)^2*(3*n-1)*a(n-3). - Vaclav Kotesovec, Mar 15 2014
a(n) ~ c * d^n / n, where d = 12*2^(2/3)+15*2^(1/3)+19 = 56.947628372041491... and c = 0.2805916350775843477992461458421909485724690193829181355064... = sqrt((6 + 5*2^(1/3) + 4*2^(2/3))/6)/(2*Pi). - Vaclav Kotesovec, Mar 15 2014, updated Mar 22 2016
From Peter Bala, Jan 16 2020: (Start)
a(n) = Sum_{0 <= j, k <= n} C(n,k)*C(n,j)*C(n+k,k)*C(n+k+j,k+j). Cf. A001850 and A274668.
a(n) = Sum_{0 <= j, k <= n} (-2)^(j+k)*C(n,k)*C(n,j)*C(n+k,k)*C(n+k+j,k+j). (End)

Extensions

More terms from Max Alekseyev, Mar 03 2007

A237252 Irregular triangle read by rows: T(n,k) = Sum_{i=0..k} (-1)^i * binomial(6*n+1,i) * binomial(k+6-i,6)^n, 0 <= k <= 6*(n-1).

Original entry on oeis.org

1, 1, 36, 225, 400, 225, 36, 1, 1, 324, 15606, 233300, 1424925, 4050864, 5703096, 4050864, 1424925, 233300, 15606, 324, 1, 1, 2376, 554931, 35138736, 879018750, 10490842656, 66555527346, 239677178256, 509723668476, 654019630000, 509723668476, 239677178256, 66555527346, 10490842656, 879018750, 35138736, 554931, 2376, 1
Offset: 1

Author

Yahia Kahloune, Feb 05 2014

Keywords

Comments

In general, define b(k,e,p) = Sum_{i=0..k} (-1)^i*binomial(e*p+1,i)*binomial(k+e-i,e)^p. Then T(n,k) = b(k,6,n).
Using these coefficients we can obtain formulas for binomial(n,e)^p and for Sum_{i=1..n} binomial(e-1+i,e)^p.
In particular:
binomial(n, e)^p = Sum_{k=0..e*(p-1)} b(k,e p) * binomial(n+k, e*p).
Sum_{i=1..n} binomial(e-1+i, e)^p = Sum_{k=0..e*(p-1)} b(k,e,p) * binomial(n+e+k, e*p+1).
T(n,k) is the number of permutations of 6 indistinguishable copies of 1..n with exactly k descents. A descent is a pair of adjacent elements with the second element less than the first. - Andrew Howroyd, May 06 2020

Examples

			For example :
  T(n,0) = 1;
  T(n,1) = 7^n - (6*n+1);
  T(n,2) = 28^n - (6*n+1)*7^n + C(6*n+1,2);
  T(n,3) = 84^n - (6*n+1)*28^n + C(6*n+1,2)*7^n + C(6*n+1,3);
  T(n,4) = 210^n - (6*n+1)*84^n + C(6*n+1,2)*28^n - C(6*n+1,3)*7^n + C(6*n+1,4).
Triangle T(n,k) begins:
 1;
 1, 36, 225, 400, 225, 36, 1;
 1, 324, 15606, 233300, 1424925, 4050864, 5703096, 4050864, 1424925, 233300, 15606, 324, 1;
 1, 2376, 554931, 35138736, 879018750, 10490842656, 66555527346, 239677178256, 509723668476, 654019630000, 509723668476, 239677178256, 66555527346, 10490842656, 879018750, 35138736, 554931, 2376, 1;
 1, 16776, 16689816, 3656408776, 286691702976, 10255094095176, 192698692565176, 2080037792142216, 13690633212385551, 57229721552316976, 156200093827061616, 283397584598631216, 345271537321293856, 283397584598631216, 156200093827061616, 57229721552316976,13690633212385551, 2080037792142216, 192698692565176, 10255094095176, 286691702976, 3656408776, 16689816, 16776, 1;
...
Example:
Sum_{i=1..n} C(5+i,6)^2 = A086027(n) = C(n+6,13) + 36*C(n+7,13) + 225*C(n+8,13) + 400*C(n+9,13) + 225*C(n+10,13) + 36*C(n+11,13) + C(n+12,13).
binomial(n,6)^2 = C(n,12) + 36*C(n+1,12) + 225*C(n+2,12) + 400*C(n+3,12) + 225*C(n+4,12) + 36*C(n+5,12) + C(n+6,12).
		

Crossrefs

Columns k=2..6 are A151651, A151652, A151653, A151654, A151655.
Row sums are A248814.
Similar triangles for e=1..5: A173018 (or A008292), A154283, A174266, A236463, A237202.
Sum_{i=1..n} binomial(5+i,6)^p for p=1..3 gives: A000580, A086027, A086028.

Programs

  • Mathematica
    b[k_, 6, p_] := Sum[(-1)^i*Binomial[6*p+1, i]*Binomial[k-i, 6]^p /. k -> 6+i, {i, 0, k-6}]; row[p_] := Table[b[k, 6, p], {k, 6, 6*p}]; Table[row[p], {p, 1, 5}] // Flatten (* Jean-François Alcover, Feb 05 2014 *)
  • PARI
    T(n,k)={sum(i=0, k, (-1)^i*binomial(6*n+1, i)*binomial(k+6-i, 6)^n)} \\ Andrew Howroyd, May 06 2020

Formula

Sum_{i=1..n} binomial(5+i,6)^p = Sum{k=0..6*(p-1)} T(p,k) * binomial(n+6+k, 6*p+1).
binomial(n,6)^p = Sum_{k=0..6*(p-1)} T(p,k) * binomial(n+k, 6*p).

Extensions

Edited by Andrew Howroyd, May 06 2020

A237202 Irregular triangle read by rows: T(n,k) = Sum_{i=0..k} (-1)^i * binomial(5*n+1,i) * binomial(k+5-i,5)^n, 0 <= k <= 5*(n-1).

Original entry on oeis.org

1, 1, 25, 100, 100, 25, 1, 1, 200, 5925, 52800, 182700, 273504, 182700, 52800, 5925, 200, 1, 1, 1275, 167475, 6021225, 84646275, 554083761, 1858142825, 3363309675, 3363309675, 1858142825, 554083761, 84646275
Offset: 1

Author

Yahia Kahloune, Feb 05 2014

Keywords

Comments

In general, define b(k,e,p) = Sum_{i=0..k} (-1)^i*binomial(e*p+1,i)*binomial(k+e-i,e)^p. Then T(n,k) = b(k,5,n).
Using these coefficients we can obtain formulas for binomial(n,e)^p and for Sum_{i=1..n} binomial(e-1+i,e)^p.
In particular:
binomial(n, e)^p = Sum_{k=0..e*(p-1)} b(k,e,p) * binomial(n+k, e*p).
Sum_{i=1..n} binomial(e-1+i, e)^p = Sum_{k=0..e*(p-1)} b(k,e,p) * binomial(n+e+k, e*p+1).
T(n,k) is the number of permutations of 5 indistinguishable copies of 1..n with exactly k descents. A descent is a pair of adjacent elements with the second element less than the first. - Andrew Howroyd, May 08 2020

Examples

			T(n,0) = 1;
T(n,1) = 6^n - (5*n+1);
T(n,2) = 21^n - (5*n+1)*6^n + C(5*n+1,2);
T(n,3) = 56^n - (5*n+1)*21^n + C(5*n+1,2)*6^n - C(5*n+1,3) ;
T(n,4) = 126^n - (5*n+1)*56^n + C(5*n+1,2)*21^n - C(5*n+1,3)*6^n  + C(5*n+1,4).
Triangle T(n,k) begins:
1;
1, 25, 100, 100, 25, 1;
1, 200, 5925, 52800, 182700, 273504, 182700, 52800, 5925, 200, 1;
1, 1275, 167475, 6021225, 84646275, 554083761, 1858142825, 3363309675, 3363309675, 1858142825, 554083761, 84646275, 6021225, 167475, 125, 1;
1, 7750, 3882250, 447069750, 18746073375, 359033166276, 3575306548500, 20052364456500, 66640122159000, 135424590593500, 171219515211316, 135424590593500, 66640122159000, 20052364456500, 3575306548500, 359033166276, 18746073375, 447069750, 3882250, 7750, 1;
...
Example:
Sum_{i=1..n} C(4+i,5)^3 = C(n+5,16) + 200*C(n+6,16) + 5925*(n+7,16) + 52800*C(n+8,16) + 182700*C(n+9,16) + 273504*C(n+10,16) + 182700*C(n+11,16) + 52800*C(n+12,16) + 5925*C(n+13,16) + 200*C(n+14,16) + C(n+15,16).
C(n,5)^3 = C(n,15) + 200*C(n+1,15) + 5925*C(n+2,15) + 52800*C(n+3,15) + 182700*C(n+4,15) + 273504*C(n+5,15) + 182700*C(n+6,15) + 52800*C(n+7,15) + 5925*C(n+8,15) + 200*C(n+9,15) + C(n+10,15).
		

Crossrefs

Columns k=2..5 are A151647, A151648, A151649, A151650.
Row sums are A014609.
Similar triangles for e=1..6: A173018 (or A008292), A154283, A174266, A236463, this sequence, A237252.
Sum_{i=1..n} binomial(4+i,5)^p for p=2..3 gives: A086025, A086026.

Programs

  • Mathematica
    b[k_, 5, p_] := Sum[(-1)^i*Binomial[5*p+1, i]*Binomial[k-i, 5]^p /. k -> 5+i, {i, 0, k-5}]; row[p_] := Table[b[k, 5, p], {k, 5, 5*p}]; Table[row[p], {p, 1, 5}] // Flatten (* Jean-François Alcover, Feb 05 2014 *)
  • PARI
    T(n,k)={sum(i=0, k, (-1)^i*binomial(5*n+1, i)*binomial(k+5-i, 5)^n)} \\ Andrew Howroyd, May 08 2020

Formula

Sum_{i=1..n} binomial(4+i,5)^p = Sum{k=0..5*(p-1)} T(p,k) * binomial(n+5+k, 5*p+1).
binomial(n,5)^p = Sum_{k=0..5*(p-1)} T(p,k) * binomial(n+k, 5*p).

Extensions

Edited by Andrew Howroyd, May 08 2020

A183205 a(n) = [x^n] (1-x)^(3n+1)/(n+1) * Sum_{k>=0} C(n+k-1,k)^3*x^k.

Original entry on oeis.org

1, 2, 16, 190, 2768, 45584, 814728, 15439974, 305760400, 6265985440, 131980086368, 2843029539376, 62400628835608, 1391503990134080, 31454839290752912, 719470742267557110, 16627360903974831120, 387786053931422003360
Offset: 0

Author

Paul D. Hanna, Dec 30 2010

Keywords

Crossrefs

Programs

  • PARI
    {a(n)=polcoeff((1-x)^(3*n+1)/(n+1)*sum(j=0, 2*n, binomial(n+j, j)^3*x^j), n)}

Formula

a(n) = A183204(n)/(n+1), where A183204 equals the central terms of triangle A181544.

A262014 Triangle in which the g.f. for row n is (1-x)^(4*n+1) * Sum_{j>=0} binomial(n+j-1,j)^4 * x^j, read by rows of k=0..3*n terms.

Original entry on oeis.org

1, 1, 11, 11, 1, 1, 72, 603, 1168, 603, 72, 1, 1, 243, 6750, 49682, 128124, 128124, 49682, 6750, 243, 1, 1, 608, 40136, 724320, 4961755, 15018688, 21571984, 15018688, 4961755, 724320, 40136, 608, 1, 1, 1275, 167475, 6021225, 84646275, 554083761, 1858142825, 3363309675, 3363309675, 1858142825, 554083761, 84646275, 6021225, 167475, 1275, 1, 1, 2376, 554931, 35138736, 879018750, 10490842656, 66555527346, 239677178256, 509723668476, 654019630000, 509723668476
Offset: 0

Author

Paul D. Hanna, Sep 10 2015

Keywords

Examples

			Triangle begins:
 1;
 1, 11, 11, 1;
 1, 72, 603, 1168, 603, 72, 1;
 1, 243, 6750, 49682, 128124, 128124, 49682, 6750, 243, 1;
 1, 608, 40136, 724320, 4961755, 15018688, 21571984, 15018688, 4961755, 724320, 40136, 608, 1;
 1, 1275, 167475, 6021225, 84646275, 554083761, 1858142825, 3363309675, 3363309675, 1858142825, 554083761, 84646275, 6021225, 167475, 1275, 1;
 1, 2376, 554931, 35138736, 879018750, 10490842656, 66555527346, 239677178256, 509723668476, 654019630000, 509723668476, 239677178256, 66555527346, 10490842656, 879018750, 35138736, 554931, 2376, 1;
 ...
Row g.f.s begin:
 n=0: (1) = (1-x) * (1 + x + x^2 + x^3 + x^4 +...);
 n=1: (1 + 11*x + 11*x^2 + x^3)  =  (1-x)^5 * (1 + 2^4*x + 3^4*x^2 + 4^4*x^3 + 5^4*x^4 + 6^4*x^5 +...);
 n=2: (1 + 72*x + 603*x^2 + 1168*x^3 + 603*x^4 + 72*x^5 + x^6)  =  (1-x)^9 * (1 + 3^4*x + 6^4*x^2 + 10^4*x^3 + 15^4*x^5 + 21^4*x^6 +...);
 n=3: (1 + 243*x + 6750*x^2 + 49682*x^3 + 128124*x^4 + 128124*x^5 + 49682*x^6 + 6750*x^7 + 243*x^8 + x^9)  =  (1-x)^13 * (1 + 4^4*x + 10^4*x^2 + 20^4*x^3 + 35^4*x^4 + 56^4*x^5 + 84^4*x^6 +...);
 ...
		

Crossrefs

Cf. A008977 (row sums), A262015 (diagonal), A202750, A258402.
Cf. A181544 (triangle variant).

Programs

  • PARI
    {T(n, k)=polcoeff(sum(j=0, n+k, binomial(n+j, j)^4*x^j)*(1-x)^(4*n+1), k)}
    for(n=0, 10, for(k=0, 3*n, print1(T(n, k), ", ")); print(""))

Formula

Row sums form A008977(n) = (4*n)!/(n!)^4.
T(n,1) = A258402(n) = (n^2 + 4*n + 6) * n^2.
From Sergii Voloshyn, Dec 17 2024: (Start)
Let E be the operator D*x*D*x*D*x*D, where D denotes the derivative operator d/dx. Then (1/(n)!^4) * E^n(1/(1 - x)) = (row n generating polynomial)/(1 - x)^(4*n+1) = Sum_{j>=0} binomial(n+j,j)^4 * x^j.
For example, when n = 2 we have (1/2!)^4*E^3(1/(1 - x)) = (1 + 243 x + 6750 x^2 + 49682 x^3 + 128124 x^4 + 128124 x^5 + 49682 x^6 + 6750 x^7 + 243 x^8 + x^9)/(1 - x)^13. (End)
Showing 1-10 of 10 results.