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 16 results. Next

A168291 T(n,k) = 4*A046802(n+1,k+1) - 2*A008518(n,k) - A007318(n,k), triangle read by rows (0 <= k <= n).

Original entry on oeis.org

1, 1, 1, 1, 6, 1, 1, 15, 15, 1, 1, 32, 82, 32, 1, 1, 65, 330, 330, 65, 1, 1, 130, 1159, 2304, 1159, 130, 1, 1, 259, 3801, 13195, 13195, 3801, 259, 1, 1, 516, 12016, 67316, 117170, 67316, 12016, 516, 1, 1, 1029, 37212, 319332, 889230, 889230, 319332, 37212
Offset: 0

Views

Author

Roger L. Bagula, Nov 22 2009

Keywords

Examples

			Triangle begins:
     1;
     1,   1;
     1,   6,     1;
     1,  15,    15,     1;
     1,  32,    82,    32,      1;
     1,  65,   330,   330,     65,     1;
     1, 130,  1159,  2304,   1159,   130,     1;
     1, 259,  3801, 13195,  13195,  3801,   259,   1;
     1, 516, 12016, 67316, 117170, 67316, 12016, 516, 1;
      ... reformatted. - _Franck Maminirina Ramaharo_, Oct 21 2018
		

Crossrefs

Triangles related to Eulerian numbers: A008292, A046802, A060187, A123125.

Programs

Formula

E.g.f.: 4*(1 - x)*exp(t)/(1 - x*exp(t*(1 - x))) - 2*(exp(t) - x*exp(t*x))/(exp(t*x) - x*exp(t)) - exp(t*(1 + x)).

Extensions

Edited, new name by Franck Maminirina Ramaharo, Oct 21 2018

A168292 T(n,k) = 24*A046802(n+1,k+1) - 9*A008518(n,k) - 8*A007318(n,k), triangle read by rows (0 <= k <= n).

Original entry on oeis.org

7, 7, 7, 7, 38, 7, 7, 99, 99, 7, 7, 220, 546, 220, 7, 7, 461, 2236, 2236, 461, 7, 7, 942, 8001, 15596, 8001, 942, 7, 7, 1903, 26697, 89921, 89921, 26697, 1903, 7, 7, 3824, 85660, 463520, 796594, 463520, 85660, 3824, 7, 7, 7665, 268530, 2224350, 6068400
Offset: 0

Views

Author

Roger L. Bagula, Nov 22 2009

Keywords

Examples

			Triangle begins:
     7;
     7,    7;
     7,   38,     7;
     7,   99,    99,      7;
     7,  220,   546,    220,      7;
     7,  461,  2236,   2236,    461,      7;
     7,  942,  8001,  15596,   8001,    942,     7;
     7, 1903, 26697,  89921,  89921,  26697,  1903,    7;
     7, 3824, 85660, 463520, 796594, 463520, 85660, 3824, 7;
      ... reformatted. - _Franck Maminirina Ramaharo_, Oct 21 2018
		

Crossrefs

Triangles related to Eulerian numbers: A008292, A046802, A060187, A123125.

Programs

Formula

E.g.f.: 24*(1 - x)*exp(t)/(1 - x*exp(t*(1 - x))) - 9*(exp(t) - x*exp(t*x))/(exp(t*x) - x*exp(t)) - 8*exp(t*(1 + x)).

Extensions

Edited, new name from Franck Maminirina Ramaharo, Oct 21 2018

A168293 T(n,k) = 12*A046802(n+1,k+1) - 9*A008518(n,k) - 2*A007318(n,k), triangle read by rows (0 <= k <= n).

Original entry on oeis.org

1, 1, 1, 1, 14, 1, 1, 33, 33, 1, 1, 64, 186, 64, 1, 1, 119, 724, 724, 119, 1, 1, 222, 2415, 5120, 2415, 222, 1, 1, 421, 7491, 28799, 28799, 7491, 421, 1, 1, 812, 22456, 142268, 257866, 142268, 22456, 812, 1, 1, 1587, 66342, 649554, 1934544, 1934544, 649554
Offset: 0

Views

Author

Roger L. Bagula, Nov 22 2009

Keywords

Examples

			Triangle begins:
    1;
    1,   1;
    1,  14,     1;
    1,  33,    33,      1;
    1,  64,   186,     64,      1;
    1, 119,   724,    724,    119,      1;
    1, 222,  2415,   5120,   2415,    222,     1;
    1, 421,  7491,  28799,  28799,   7491,   421,   1;
    1, 812, 22456, 142268, 257866, 142268, 22456, 812, 1:
     ... reformatted. - _Franck Maminirina Ramaharo_, Oct 21 2018
		

Crossrefs

Triangles related to Eulerian numbers: A008292, A046802, A060187, A123125.

Programs

Formula

E.g.f.: 12*(1 - x)*exp(t)/(1 - x*exp(t*(1 - x))) - 9*(exp(t) - x*exp(t*x))/(exp(t*x) - x*exp(t)) - 2*exp(t*(1 + x)).

Extensions

Edited, and new name by Franck Maminirina Ramaharo, Oct 21 2018

A000325 a(n) = 2^n - n.

Original entry on oeis.org

1, 1, 2, 5, 12, 27, 58, 121, 248, 503, 1014, 2037, 4084, 8179, 16370, 32753, 65520, 131055, 262126, 524269, 1048556, 2097131, 4194282, 8388585, 16777192, 33554407, 67108838, 134217701, 268435428, 536870883, 1073741794, 2147483617
Offset: 0

Views

Author

Rosario Salamone (Rosario.Salamone(AT)risc.uni-linz.ac.at)

Keywords

Comments

Number of permutations of degree n with at most one fall; called "Grassmannian permutations" by Lascoux and Schützenberger. - Axel Kohnert (Axel.Kohnert(AT)uni-bayreuth.de)
Number of different permutations of a deck of n cards that can be produced by a single shuffle. [DeSario]
Number of Dyck paths of semilength n having at most one long ascent (i.e., ascent of length at least two). Example: a(4)=12 because among the 14 Dyck paths of semilength 4, the only paths that have more than one long ascent are UUDDUUDD and UUDUUDDD (each with two long ascents). Here U = (1, 1) and D = (1, -1). Also number of ordered trees with n edges having at most one branch node (i.e., vertex of outdegree at least two). - Emeric Deutsch, Feb 22 2004
Number of {12,1*2*,21*}-avoiding signed permutations in the hyperoctahedral group.
Number of 1342-avoiding circular permutations on [n+1].
2^n - n is the number of ways to partition {1, 2, ..., n} into arithmetic progressions, where in each partition all the progressions have the same common difference and have lengths at least 1. - Marty Getz (ffmpg1(AT)uaf.edu) and Dixon Jones (fndjj(AT)uaf.edu), May 21 2005
if b(0) = x and b(n) = b(n-1) + b(n-1)^2*x^(n-2) for n > 0, then b(n) is a polynomial of degree a(n). - Michael Somos, Nov 04 2006
The chromatic invariant of the Mobius ladder graph M_n for n >= 2. - Jonathan Vos Post, Aug 29 2008
Dimension sequence of the dual alternative operad (i.e., associative and satisfying the identity xyz + yxz + zxy + xzy + yzx + zyx = 0) over the field of characteristic 3. - Pasha Zusmanovich, Jun 09 2009
An elephant sequence, see A175654. For the corner squares six A[5] vectors, with decimal values between 26 and 176, lead to this sequence (without the first leading 1). For the central square these vectors lead to the companion sequence A168604. - Johannes W. Meijer, Aug 15 2010
a(n+1) is also the number of order-preserving and order-decreasing partial isometries (of an n-chain). - Abdullahi Umar, Jan 13 2011
A040001(n) = p(-1) where p(x) is the unique degree-n polynomial such that p(k) = a(k) for k = 0, 1, ..., n. - Michael Somos, May 12 2012
A130103(n+1) = p(n+1) where p(x) is the unique degree-n polynomial such that p(k) = a(k) for k = 0, 1, ..., n. - Michael Somos, May 12 2012
The number of labeled graphs with n vertices whose vertex set can be partitioned into a clique and a set of isolated points. - Alex J. Best, Nov 20 2012
For n > 0, a(n) is a B_2 sequence. - Thomas Ordowski, Sep 23 2014
See coefficients of the linear terms of the polynomials of the table on p. 10 of the Getzler link. - Tom Copeland, Mar 24 2016
Consider n points lying on a circle, then for n>=2 a(n-1) is the maximum number of ways to connect two points with non-intersecting chords. - Anton Zakharov, Dec 31 2016
Also the number of cliques in the (n-1)-triangular honeycomb rook graph. - Eric W. Weisstein, Jul 14 2017
From Eric M. Schmidt, Jul 17 2017: (Start)
Number of sequences (e(1), ..., e(n)), 0 <= e(i) < i, such that there is no triple i < j < k with e(i) != e(j) < e(k). [Martinez and Savage, 2.7]
Number of sequences (e(1), ..., e(n)), 0 <= e(i) < i, such that there is no triple i < j < k with e(i), e(j), e(k) pairwise distinct. [Martinez and Savage, 2.7]
Number of sequences (e(1), ..., e(n)), 0 <= e(i) < i, such that there is no triple i < j < k with e(j) >= e(k) and e(i) != e(k) pairwise distinct. [Martinez and Savage, 2.7]
(End)
Number of F-equivalence classes of Łukasiewicz paths. Łukasiewicz paths are F-equivalent iff the positions of pattern F are identical in these paths. - Sergey Kirgizov, Apr 08 2018
From Gus Wiseman, Feb 10 2019: (Start)
Also the number of connected partitions of an n-cycle. For example, the a(1) = 1 through a(4) = 12 connected partitions are:
{{1}} {{12}} {{123}} {{1234}}
{{1}{2}} {{1}{23}} {{1}{234}}
{{12}{3}} {{12}{34}}
{{13}{2}} {{123}{4}}
{{1}{2}{3}} {{124}{3}}
{{134}{2}}
{{14}{23}}
{{1}{2}{34}}
{{1}{23}{4}}
{{12}{3}{4}}
{{14}{2}{3}}
{{1}{2}{3}{4}}
(End)
Number of subsets of n-set without the single-element subsets. - Yuchun Ji, Jul 16 2019
For every prime p, there are infinitely many terms of this sequence that are divisible by p (see IMO Compendium link and Doob reference). Corresponding indices n are: for p = 2, even numbers A299174; for p = 3, A047257; for p = 5, A349767. - Bernard Schott, Dec 10 2021
Primes are in A081296 and corresponding indices in A048744. - Bernard Schott, Dec 12 2021

Examples

			G.f. = 1 + x + 2*x^2 + 5*x^3 + 12*x^4 + 27*x^5 + 58*x^6 + 121*x^7 + ...
		

References

  • Michael Doob, The Canadian Mathematical Olympiad & L'Olympiade Mathématique du Canada 1969-1993, Canadian Mathematical Society & Société Mathématique du Canada, Problem 4, 1983, page 158, 1993.

Crossrefs

Column 1 of triangle A008518.
Row sum of triangles A184049 and A184050.

Programs

  • Haskell
    a000325 n = 2 ^ n - n
    a000325_list = zipWith (-) a000079_list [0..]
    -- Reinhard Zumkeller, Jul 17 2012
    
  • Magma
    [2^n - n: n in [0..35]]; // Vincenzo Librandi, May 13 2011
    
  • Maple
    A000325 := proc(n) option remember; if n <=1 then n+1 else 2*A000325(n-1)+n-1; fi; end;
    g:=1/(1-2*z): gser:=series(g, z=0, 43): seq(coeff(gser, z, n)-n, n=0..31); # Zerinvary Lajos, Jan 09 2009
  • Mathematica
    Table[2^n - n, {n, 0, 39}] (* Alonso del Arte, Sep 15 2014 *)
    LinearRecurrence[{4, -5, 2}, {1, 2, 5}, {0, 20}] (* Eric W. Weisstein, Jul 14 2017 *)
  • PARI
    {a(n) = 2^n - n}; /* Michael Somos, Nov 04 2006 */
    
  • Python
    def A000325(n): return (1<Chai Wah Wu, Jan 11 2023

Formula

a(n+1) = 2*a(n) + n - 1, a(0) = 1. - Reinhard Zumkeller, Apr 12 2003
Binomial transform of 1, 0, 1, 1, 1, .... The sequence starting 1, 2, 5, ... has a(n) = 1 + n + 2*Sum_{k=2..n} binomial(n, k) = 2^(n+1) - n - 1. This is the binomial transform of 1, 1, 2, 2, 2, 2, .... a(n) = 1 + Sum_{k=2..n} C(n, k). - Paul Barry, Jun 06 2003
G.f.: (1-3x+3x^2)/((1-2x)*(1-x)^2). - Emeric Deutsch, Feb 22 2004
A107907(a(n+2)) = A000051(n+2) for n > 0. - Reinhard Zumkeller, May 28 2005
a(n+1) = sum of n-th row of the triangle in A109128. - Reinhard Zumkeller, Jun 20 2005
Row sums of triangle A133116. - Gary W. Adamson, Sep 14 2007
G.f.: 1 / (1 - x / (1 - x / ( 1 - x / (1 + x / (1 - 2*x))))). - Michael Somos, May 12 2012
First difference is A000225. PSUM transform is A084634. - Michael Somos, May 12 2012
a(n) = [x^n](B(x)^n-B(x)^(n-1)), n>0, a(0)=1, where B(x) = (1+2*x+sqrt(1+4*x^2))/2. - Vladimir Kruchinin, Mar 07 2014
E.g.f.: (exp(x) - x)*exp(x). - Ilya Gutkovskiy, Aug 07 2016
a(n) = A125128(n) - A000225(n) + 1. - Miquel Cerda, Aug 12 2016
a(n) = 2*A125128(n) - A095151(n) + 1. - Miquel Cerda, Aug 12 2016
a(n) = A079583(n-1) - A000225(n-1). - Miquel Cerda, Aug 15 2016
a(n)^2 - 4*a(n-1)^2 = (n-2)*(a(n)+2*a(n-1)). - Yuchun Ji, Jul 13 2018
a(n) = 2^(-n) * A186947(n) = 2^n * A002064(-n) for all n in Z. - Michael Somos, Jul 18 2018
a(2^n) = (2^a(n) - 1)*2^n. - Lorenzo Sauras Altuzarra, Feb 01 2022

A098558 Expansion of e.g.f. (1+x)/(1-x).

Original entry on oeis.org

1, 2, 4, 12, 48, 240, 1440, 10080, 80640, 725760, 7257600, 79833600, 958003200, 12454041600, 174356582400, 2615348736000, 41845579776000, 711374856192000, 12804747411456000, 243290200817664000, 4865804016353280000, 102181884343418880000, 2248001455555215360000
Offset: 0

Views

Author

Paul Barry, Sep 14 2004

Keywords

Comments

Essentially the same as A052849: a(0)=0 and a(n) = A052849(n) for n>=1.
Equals row sums (unsigned) of triangle A158471. - Gary W. Adamson, Mar 20 2009
Also the number of graceful labelings of the star graph on n+1 nodes. - Eric W. Weisstein, Mar 31 2020

Crossrefs

Row sums of A008518 and of A128564.
Cf. A158471.

Programs

  • Magma
    [1] cat [2*Factorial(n): n in [1..30]]; // G. C. Greubel, Jan 17 2018
    
  • Mathematica
    Join[{1}, 2*Range[30]!] (* G. C. Greubel, Jan 17 2018 *)
    With[{nn=30},CoefficientList[Series[(1+x)/(1-x),{x,0,nn}],x] Range[0,nn]!] (* Harvey P. Dale, Jun 05 2021 *)
    a[n_] := Hypergeometric2F1Regularized[1, -n, 2 - n, -1];
    Table[a[n], {n, 0, 22}]  (* Peter Luschny, Apr 26 2024 *)
  • PARI
    concat([1], vector(30, n, 2*n!)) \\ G. C. Greubel, Jan 17 2018
    
  • SageMath
    CF = ComplexBallField(100)
    def a(n):
        return Integer(CF(-1).hypergeometric([1, -n], [2 - n], regularized=True))
    print([a(n) for n in range(23)]) # Peter Luschny, Apr 26 2024

Formula

a(n) = 2*n! - 0^n.
a(n) = Sum_{k=0..n} (k+1) * A008290(n,k). - Alois P. Heinz, Mar 11 2022
Sum_{n>=0} 1/a(n) = (e+1)/2. - Amiram Eldar, Feb 02 2023
a(n) = HypergeomRegularized([1, -n], [2 - n], -1). - Peter Luschny, Apr 26 2024

A177042 Eulerian version of the Catalan numbers, a(n) = A008292(2*n+1,n+1)/(n+1).

Original entry on oeis.org

1, 2, 22, 604, 31238, 2620708, 325024572, 55942352184, 12765597850950, 3730771315561300, 1359124435588313876, 603916464771468176392, 321511316149669476991132, 202039976682357297272094824, 147980747895225006590333244088, 124963193751534047864734415925360
Offset: 0

Views

Author

Roger L. Bagula, May 01 2010

Keywords

Comments

According to the Bidkhori and Sullivant reference's abstract, authors show "that the Eulerian-Catalan numbers enumerate Dyck permutations, [providing] two proofs for this fact, the first using the geometry of alcoved polytopes and the second a direct combinatorial proof via an Eulerian-Catalan analog of the Chung-Feller theorem." - Jonathan Vos Post, Jan 07 2011
Twice the number of permutations of {1,2,...,2n} with n ascents. - Peter Luschny, Jan 11 2011

Crossrefs

Bisection (odd part) of A303287.
Row sums of A316728.

Programs

  • Magma
    A177042:=func< n | n eq 0 select 1 else 2*(&+[(-1)^k*Binomial(2*n+1,k)*(n-k+1)^(2*n): k in [0..n]]) >;
    [A177042(n): n in [0..40]]; // G. C. Greubel, Jun 18 2024
    
  • Maple
    A177042 := proc(n) A008292(2*n+1,n+1)/(n+1) ; end proc:
    seq(A177042(n),n=0..10) ; # R. J. Mathar, Jan 08 2011
    A177042 := n -> A025585(n+1)/(n+1):
    A177042 := n -> `if`(n=0,1,2*A180056(n)):
    # The A173018-based recursion below needs no division!
    A := proc(n, k) option remember;
           if n = 0 and k = 0 then 1
         elif k > n  or k < 0 then 0
         else (n-k) *A(n-1, k-1) +(k+1) *A(n-1, k)
           fi
         end:
    A177042 := n-> `if`(n=0, 1, 2*A(2*n, n)):
    seq(A177042(n), n=0..30);
    # Peter Luschny, Jan 11 2011
  • Mathematica
    << DiscreteMath`Combinatorica`
    Table[(Eulerian[2*n + 1, n])/(n + 1), {n, 0, 20}]
    (* Second program: *)
    A[n_, k_] := A[n, k] = Which[n == 0 && k == 0, 1, k > n || k < 0, 0, True, (n - k)*A[n - 1, k - 1] + (k + 1)*A[n - 1, k]]; A177042[n_] := If[n == 0, 1, 2*A[2*n, n]]; Table[A177042[n], {n, 0, 30}] (* Jean-François Alcover, Jul 13 2017, after Peter Luschny *)
  • SageMath
    def A177042(n): return 2*sum((-1)^k*binomial(2*n+1,k)*(n-k+1)^(2*n) for k in range(n+1)) - int(n==0)
    [A177042(n) for n in range(41)] # G. C. Greubel, Jun 18 2024

Formula

a(n) = 2*A180056(n) for n > 0, A180056 the central Eulerian numbers in the sense of A173018.
a(n) = A025585(n+1)/(n+1), A025585 the central Eulerian numbers in the sense of A008292.
a(n) = 2 Sum_{k=0..n} (-1)^k binomial(2n+1,k) (n-k+1)^(2n).
a(n) = (n+1)^(-1) Sum_{k=0..n} (-1)^k binomial(2n+2,k)(n+1-k)^(2n+1). - Peter Luschny, Jan 11 2011
a(n) = A008518(2n,n). - Alois P. Heinz, Jun 12 2017
From Alois P. Heinz, Jul 21 2018: (Start)
a(n) = (2n)! * [x^(2n) y^n] (exp(x)-y*exp(y*x))/(exp(y*x)-y*exp(x)).
a(n) = (2n+1)!/(n+1) * [x^(2n+1) y^(n+1)] (1-y)/(1-y*exp((1-y)*x)). (End)

Extensions

Edited by Alois P. Heinz, Jan 14 2011

A174599 Triangle T(n, k) = A154646(n,k) - A154646(n,0) + 1, 0 <= k <= n.

Original entry on oeis.org

1, 1, 1, 1, 22, 1, 1, 145, 145, 1, 1, 780, 2246, 780, 1, 1, 3919, 25144, 25144, 3919, 1, 1, 19202, 243047, 524812, 243047, 19202, 1, 1, 93349, 2168107, 8760511, 8760511, 2168107, 93349, 1, 1, 453592, 18445564, 127880680, 235517062, 127880680, 18445564, 453592, 1
Offset: 0

Views

Author

Roger L. Bagula, Mar 23 2010

Keywords

Comments

The first and last element of each row of A154646 are reduced to 1 by subtracting a constant from each row.

Examples

			Triangle begins as:
  1;
  1,     1;
  1,    22,       1;
  1,   145,     145,       1;
  1,   780,    2246,     780,       1;
  1,  3919,   25144,   25144,    3919,       1;
  1, 19202,  243047,  524812,  243047,   19202,     1;
  1, 93349, 2168107, 8760511, 8760511, 2168107, 93349,    1;
		

Crossrefs

Related triangles dependent on q: A008518 (q=1), A176198 (q=2), this sequence (q=3), A176199 (q=4).
Cf. A154646.

Programs

  • Magma
    m:=13;
    R:=PowerSeriesRing(Integers(), m+2);
    p:= func< x,n,q | (1-x)^(n+1)*(&+[((q*j+1)^n + (q*(j+1)-1)^n)*x^j: j in [0..m+2]]) >;
    f:= func< n,k,q | Coefficient(R!( p(x,n,q) ), k) >;
    T:= func< n,k,q | f(n,k,q) -f(n,0,q) +1 >; // T = A174599
    [T(n,k,3): k in [0..n], n in [0..m]]; // G. C. Greubel, Jun 18 2024
    
  • Mathematica
    m:=13;
    p[x_,n_,q_]:= (1-x)^(n+1)*Sum[((q*j+1)^n+(q*(j+1)-1)^n)*x^j, {j,0,m+2}];
    f[n_,k_,q_]:= Coefficient[Series[p[x,n,q], {x,0,m+2}], x, k];
    T[n_,k_,q_]:= f[n,k,q] -f[n,0,q] +1;
    Table[T[n,k,3], {n,0,m}, {k,0,n}]//Flatten
  • SageMath
    m=13
    def p(x,n,q): return (1-x)^(n+1)*sum(((q*j+1)^n + (q*(j+1)-1)^n)*x^j for j in range(m+3))
    def f(n,k,q): return ( p(x,n,q) ).series(x, n+1).list()[k]
    def T(n,k,q): return f(n,k,q) - f(n,0,q) + 1 # T = A174599
    flatten([[T(n,k,3) for k in range(n+1)] for n in (0..m)]) # G. C. Greubel, Jun 18 2024

Formula

From G. C. Greubel, Jun 18 2024: (Start)
T(n, k) = f(n, k, q) - f(n, 0, q) + 1, where f(n, k, q) = [x^k]( p(x, n, q) ), p(x, n, q) = (1-x)^(n+1) * Sum_{k >= 0} ( (q*k + 1)^n + (q*(k+1) - 1)^n )*x^k, and q = 3.
T(n, k) f(n, k, q) - f(n, 0, q) + 1, where f(n, k, q) = [x^k]( p(x, n, q) ), p(x, n, q) = q^n * (1-x)^(n+1) * ( LerchPhi(x, -n, 1/q) + LerchPhi(x, -n, (q-1)/q) ), and q = 3.
T(n, k) = A154646(n,k) - A154646(n,0) + 1.
T(n, n-k) = T(n, k). (End)

A176198 Triangle, read by rows, T(n, k) = f(n,k,q) - f(n,0,q) + 1, where f(n, k, q) = [x^k](p(x,n,q)), p(x, n, q) = (1-x)^(n+1)*Sum_{k >= 0} ( (q*k+1)^n + (q*(k+1)-1)^n )*x^k, and q = 2.

Original entry on oeis.org

1, 1, 1, 1, 11, 1, 1, 45, 45, 1, 1, 151, 459, 151, 1, 1, 473, 3363, 3363, 473, 1, 1, 1443, 21085, 47095, 21085, 1443, 1, 1, 4357, 121313, 519445, 519445, 121313, 4357, 1, 1, 13103, 663223, 4970575, 9350027, 4970575, 663223, 13103, 1, 1, 39345, 3512679, 43415943, 138826587, 138826587, 43415943, 3512679, 39345, 1
Offset: 0

Views

Author

Roger L. Bagula, Apr 11 2010

Keywords

Examples

			Triangle begins as:
  1;
  1,     1;
  1,    11,      1;
  1,    45,     45,       1;
  1,   151,    459,     151,       1;
  1,   473,   3363,    3363,     473,       1;
  1,  1443,  21085,   47095,   21085,    1443,      1;
  1,  4357, 121313,  519445,  519445,  121313,   4357,     1;
  1, 13103, 663223, 4970575, 9350027, 4970575, 663223, 13103,     1;
		

Crossrefs

Related triangles dependent on q: A008518 (q=1), this sequence (q=2), A174599 (q=3), A176199 (q=4).

Programs

  • Magma
    m:=13;
    R:=PowerSeriesRing(Integers(), m+2);
    p:= func< x,n,q | (1-x)^(n+1)*(&+[((q*j+1)^n + (q*(j+1)-1)^n)*x^j: j in [0..m+2]]) >;
    f:= func< n,k,q | Coefficient(R!( p(x,n,q) ), k) >;
    T:= func< n,k,q | f(n,k,q) - f(n,0,q) + 1 >; // T = A176198
    [T(n,k,2): k in [0..n], n in [0..m]]; // G. C. Greubel, Jun 18 2024
    
  • Mathematica
    m:=13;
    p[x_,n_,q_]:= (1-x)^(n+1)*Sum[((q*j+1)^n+(q*(j+1)-1)^n)*x^j, {j,0,m+ 2}];
    f[n_,k_,q_]:= Coefficient[Series[p[x,n,q], {x,0,m+2}], x, k];
    T[n_,k_,q_]:= f[n,k,q] - f[n,0,q] + 1; (* T = A176198 *)
    Table[T[n,k,2], {n,0,m}, {k,0,n}]//Flatten
  • SageMath
    m=13
    def p(x,n,q): return (1-x)^(n+1)*sum(((q*j+1)^n + (q*(j+1)-1)^n)*x^j for j in range(m+3))
    def f(n,k,q): return ( p(x,n,q) ).series(x, n+1).list()[k]
    def T(n,k,q): return f(n,k,q) - f(n,0,q) + 1 # T = A176198
    flatten([[T(n,k,2) for k in range(n+1)] for n in (0..m)]) # G. C. Greubel, Jun 18 2024

Formula

T(n, k) = f(n, k, q) - f(n, 0, q) + 1, where f(n, k, q) = [x^k]( p(x, n, q) ), p(x, n, q) = (1-x)^(n+1) * Sum_{k >= 0} ( (q*k + 1)^n + (q*(k+1) - 1)^n )*x^k, and q = 2.
T(n, k) f(n, k, q) - f(n, 0, q) + 1, where f(n, k, q) = [x^k]( p(x, n, q) ), p(x, n, q) = q^n * (1-x)^(n+1) * ( LerchPhi(x, -n, 1/q) + LerchPhi(x, -n, (q-1)/q) ), and q = 2.
T(n, n-k) = T(n, k).

Extensions

Edited by G. C. Greubel, Jun 19 2024

A176199 Triangle, read by rows, T(n, k) = f(n,k,q) - f(n,0,q) + 1, where f(n, k, q) = [x^k](p(x,n,q)), p(x, n, q) = (1-x)^(n+1)*Sum_{k >= 0} ( (q*k+1)^n + (q*(k+1)-1)^n )*x^k, and q = 4.

Original entry on oeis.org

1, 1, 1, 1, 35, 1, 1, 329, 329, 1, 1, 2535, 6811, 2535, 1, 1, 18225, 103925, 103925, 18225, 1, 1, 127435, 1384685, 2868895, 1384685, 127435, 1, 1, 881977, 17115873, 64568761, 64568761, 17115873, 881977, 1, 1, 6089807, 202236439, 1283008495, 2302094507, 1283008495, 202236439, 6089807, 1
Offset: 0

Views

Author

Roger L. Bagula, Apr 11 2010

Keywords

Examples

			Triangle begins as:
  1;
  1,      1;
  1,     35,        1;
  1,    329,      329,        1;
  1,   2535,     6811,     2535,        1;
  1,  18225,   103925,   103925,    18225,        1;
  1, 127435,  1384685,  2868895,  1384685,   127435,      1;
  1, 881977, 17115873, 64568761, 64568761, 17115873, 881977,     1;
		

Crossrefs

Related triangles dependent on q: A008518 (q=1), A176198 (q=2), A174599 (q=3), this sequence (q=4).

Programs

  • Magma
    m:=13;
    R:=PowerSeriesRing(Integers(), m+2);
    p:= func< x,n,q | (1-x)^(n+1)*(&+[((q*j+1)^n + (q*(j+1)-1)^n)*x^j: j in [0..m+2]]) >;
    f:= func< n,k,q | Coefficient(R!( p(x,n,q) ), k) >;
    T:= func< n,k,q | f(n,k,q) - f(n,0,q) + 1 >; // T = A176199
    [T(n,k,4): k in [0..n], n in [0..m]]; // G. C. Greubel, Jun 18 2024
    
  • Mathematica
    m:=13;
    p[x_,n_,q_]:= (1-x)^(n+1)*Sum[((q*j+1)^n+(q*(j+1)-1)^n)*x^j, {j,0,m+ 2}];
    f[n_,k_,q_]:= Coefficient[Series[p[x,n,q], {x,0,m+2}], x, k];
    T[n_,k_,q_]:= f[n,k,q] - f[n,0,q] + 1;
    Table[T[n,k,4], {n,0,m}, {k,0,n}]//Flatten
  • SageMath
    m=13
    def p(x,n,q): return (1-x)^(n+1)*sum(((q*j+1)^n + (q*(j+1)-1)^n)*x^j for j in range(m+3))
    def f(n,k,q): return ( p(x,n,q) ).series(x, n+1).list()[k]
    def T(n,k,q): return f(n,k,q) - f(n,0,q) + 1 # T = A176199
    flatten([[T(n,k,4) for k in range(n+1)] for n in (0..m)]) # G. C. Greubel, Jun 18 2024

Formula

T(n, k) = f(n, k, q) - f(n, 0, q) + 1, where f(n, k, q) = [x^k]( p(x, n, q) ), p(x, n, q) = (1-x)^(n+1) * Sum_{k >= 0} ( (q*k + 1)^n + (q*(k+1) - 1)^n )*x^k, and q = 4.
T(n, k) f(n, k, q) - f(n, 0, q) + 1, where f(n, k, q) = [x^k]( p(x, n, q) ), p(x, n, q) = q^n * (1-x)^(n+1) * ( LerchPhi(x, -n, 1/q) + LerchPhi(x, -n, (q-1)/q) ), and q = 4.
T(n, n-k) = T(n, k).

Extensions

Edited by G. C. Greubel, Jun 18 2024

A204621 Triangle read by rows: coordinator triangle for lattice A*_n.

Original entry on oeis.org

1, 1, 1, 1, 4, 1, 1, 5, 5, 1, 1, 6, 16, 6, 1, 1, 7, 22, 22, 7, 1, 1, 8, 29, 64, 29, 8, 1, 1, 9, 37, 93, 93, 37, 9, 1, 1, 10, 46, 130, 256, 130, 46, 10, 1, 1, 11, 56, 176, 386, 386, 176, 56, 11, 1, 1, 12, 67, 232, 562, 1024, 562, 232, 67, 12, 1
Offset: 0

Views

Author

N. J. A. Sloane, Jan 17 2012

Keywords

Examples

			Triangle begins:
                   1
                1    1
              1    4    1
            1    5    5    1
          1    6    16    6    1
        1    7    22    22    7    1
      1    8    29    64    29    8    1
    1    9    37    93    93    37    9    1
  1    10    46    130    256    130    46    10    1
1     11    56    176    386    386    176    56    11    1
...
		

Crossrefs

The triangle for Z^n is A007318, A_n is A008459, D_n is A108558, D*_n is A008518.
T(2n,n) gives A000302.

Programs

  • GAP
    Flat(List([0..10],n->List([0..n],k->Sum([0..Minimum(k,n-k)],i->Binomial(n+1,i))))); # Muniru A Asiru, Dec 14 2018
  • Mathematica
    T[n_, k_] := Sum[Binomial[n+1, i] , {i, 0, Min[k, n-k]}]; Table[T[n,k], {n,0,10}, {k,0,n}] // Flatten (* Amiram Eldar, Dec 14 2018 *)

Formula

T(n, k) = Sum_{i=0..min(k,n-k)} binomial(n+1,i). [Wang and Yu, Theorem 4.1] - Eric M. Schmidt, Dec 07 2017
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