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.

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A219184 O.g.f. satisfies: A(x) = Sum_{n>=0} n^(2*n) * x^n * A(x)^n / n! * exp(-n^2*x*A(x)).

Original entry on oeis.org

1, 1, 8, 112, 2202, 55641, 1724050, 63550446, 2725133134, 133546286188, 7370574862110, 452601918694564, 30610161317492690, 2260721225822606054, 181023122013996360316, 15619416644091171417138, 1444615406376578862379054, 142565035949775130517868740
Offset: 0

Views

Author

Paul D. Hanna, Nov 13 2012

Keywords

Comments

Compare to the LambertW identity:
Sum_{n>=0} n^n * x^n * G(x)^n / n! * exp(-n*x*G(x)) = 1/(1 - x*G(x)).

Examples

			O.g.f.: A(x) = 1 + x + 8*x^2 + 112*x^3 + 2202*x^4 + 55641*x^5 + 1724050*x^6 +...
where
A(x) = 1 + x*A(x)*exp(-x*A(x)) + 2^4*x^2*A(x)^2/2!*exp(-4*x*A(x)) + 3^6*x^3*A(x)^3/3!*exp(-9*x*A(x)) + 4^8*x^4*A(x)^4/4!*exp(-16*x*A(x)) + 5^10*x^5*A(x)^5/5!*exp(-25*x*A(x)) +...
simplifies to a power series in x with integer coefficients.
O.g.f. A(x) satisfies A(x) = G(x*A(x)) where G(x) = A(x/G(x)) begins:
G(x) = 1 + x + 7*x^2 + 90*x^3 + 1701*x^4 + 42525*x^5 + 1323652*x^6 +...+ Stirling2(2*n,n)*x^n +...
so that A(x) = (1/x)*Series_Reversion(x/G(x)).
		

Crossrefs

Programs

  • PARI
    {a(n)=local(A=1);for(i=1,n,A=sum(m=0, n, (m^2*x*A)^m/m!*exp(-m^2*x*A+x*O(x^n))));polcoeff(A, n)}
    for(n=0,21,print1(a(n),", "))

Formula

O.g.f. satisfies: A(x) = Sum_{n>=0} Stirling2(2*n,n) * x^n * A(x)^n.

A222525 O.g.f.: Sum_{n>=0} (2*n+1)^(2*n) * exp(-(2*n+1)^2*x) * x^n / n!.

Original entry on oeis.org

1, 8, 232, 12160, 929376, 93590784, 11709432064, 1751777730560, 305065968649728, 60623947402670080, 13538933075023376384, 3356940619048979988480, 915040828127405123420160, 271974910674004076827115520, 87543520972441760055430348800, 30337462571518006406505729884160
Offset: 0

Views

Author

Paul D. Hanna, Feb 24 2013

Keywords

Examples

			O.g.f.: A(x) = 1 + 8*x + 232*x^2 + 12160*x^3 + 929376*x^4 + 93590784*x^5 +...
where
A(x) = exp(-x) + 3^2*exp(-3^2*x)*x + 5^4*exp(-5^2*x)*x^2/2! + 7^6*exp(-7^2*x)*x^3/3! + 9^8*exp(-9^2*x)*x^4/4! + 11^10*exp(-11^2*x)*x^5/5! +...
is a power series in x with integer coefficients.
		

Crossrefs

Programs

  • Mathematica
    Table[1/n!*Sum[(-1)^(n-k)*Binomial[n,k]*(2*k+1)^(2*n),{k,0,n}],{n,0,20}] (* Vaclav Kotesovec, May 13 2014 *)
    Table[Sum[2^k*Binomial[2*n,k]*StirlingS2[k,n],{k,n,2*n}],{n,0,20}] (* Vaclav Kotesovec, May 13 2014 *)
  • PARI
    {a(n)=polcoeff(sum(k=0, n, (2*k+1)^(2*k)*exp(-(2*k+1)^2*x +x*O(x^n))*x^k/k!), n)}
    for(n=0, 20, print1(a(n), ", "))
    
  • PARI
    {a(n)=(1/n!)*polcoeff(sum(k=0, n, (2*k+1)^(2*k)*x^k/(1+(2*k+1)^2*x +x*O(x^n))^(k+1)), n)}
    for(n=0, 20, print1(a(n), ", "))
    
  • PARI
    {a(n)=1/n!*sum(k=0, n, (-1)^(n-k)*binomial(n, k)*(2*k+1)^(2*n))}
    for(n=0, 20, print1(a(n), ", "))

Formula

a(n) = 1/n! * [x^n] Sum_{k>=0} (2*k+1)^(2*k) * x^k / (1 + (2*k+1)^2*x)^(k+1).
a(n) = 1/n! * Sum_{k=0..n} (-1)^(n-k)*binomial(n,k) * (2*k+1)^(2*n).
a(n) = Sum_{k=0..n} 2^(n+k) * binomial(2*n,n+k) * stirling2(n+k,n). - Vaclav Kotesovec, May 13 2014
a(n) ~ 2^(4*n) * n^(n-1/2) / (sqrt(Pi*r*(1-r)) * exp(n) * (r*(2-r))^n), where r = -LambertW(-2*exp(-2)) = 0.4063757399599... (see A226775 = -r). - Vaclav Kotesovec, May 13 2014

A258467 Number of partitions of 2n into parts of exactly n sorts which are introduced in ascending order.

Original entry on oeis.org

1, 2, 12, 130, 2216, 52078, 1558219, 56524414, 2406802476, 117575627562, 6478447651345, 397345158550386, 26842747368209994, 1980156804133210116, 158365138356099680582, 13647670818304698139989, 1260732993182758276252088, 124273946254095006307105363
Offset: 0

Views

Author

Alois P. Heinz, May 30 2015

Keywords

Crossrefs

Programs

  • Maple
    b:= proc(n, i, k) option remember; `if`(n=0, 1, `if`(i<1, 0,
          b(n, i-1, k) +`if`(i>n, 0, k*b(n-i, i, k))))
        end:
    T:= (n, k)-> add(b(n$2, k-i)*(-1)^i/(i!*(k-i)!), i=0..k):
    a:= n-> T(2*n, n):
    seq(a(n), n=0..20);
  • Mathematica
    b[n_, i_, k_] := b[n, i, k] = If[n==0, 1, If[i<1, 0, b[n, i-1, k] + If[i>n, 0, k*b[n-i, i, k]]]]; T[n_, k_] := Sum[b[n, n, k-i]*(-1)^i/(i!*(k-i)!), {i, 0, k}]; a[n_] := T[2n, n]; Table[a[n], {n, 0, 20}] (* Jean-François Alcover, Feb 06 2017, translated from Maple *)

Formula

a(n) = A256130(2n,n).
a(n) ~ 2^(2*n-1/2) * n^(n-1/2) / (sqrt(Pi*(1-c)) * exp(n) * c^n * (2-c)^n), where c = -A226775 = -LambertW(-2*exp(-2)) = 0.4063757399599599... . - Vaclav Kotesovec, May 31 2015
a(n) ~ Stirling2(2*n, n) = A007820(n). - Vaclav Kotesovec, Jun 01 2015

A291204 Number F(n,h,t) of forests of t labeled rooted trees with n vertices such that the root of each subtree contains the subtree's minimal label and h is the maximum of 0 and the tree heights; triangle of triangles F(n,h,t), n>=0, h=0..n, t=0..n-h, read by layers, then by rows.

Original entry on oeis.org

1, 0, 1, 0, 0, 0, 1, 0, 1, 0, 0, 0, 0, 1, 0, 1, 3, 0, 1, 0, 0, 0, 0, 0, 1, 0, 1, 7, 6, 0, 4, 4, 0, 1, 0, 0, 0, 0, 0, 0, 1, 0, 1, 15, 25, 10, 0, 14, 30, 10, 0, 8, 5, 0, 1, 0, 0, 0, 0, 0, 0, 0, 1, 0, 1, 31, 90, 65, 15, 0, 51, 174, 120, 20, 0, 54, 63, 15, 0, 13, 6, 0, 1, 0
Offset: 0

Views

Author

Alois P. Heinz, Aug 20 2017

Keywords

Comments

Elements in rows h=0 give A023531.
Positive elements in rows h=1 give A008277.
Positive row sums per layer (and - with a different offset - positive elements in column t=1) give A179454.
Positive column sums per layer give A132393.

Examples

			n h\t: 0  1  2  3  4 5 : A179454 : A132393       : A000142
-----+-----------------+---------+---------------+--------
0 0  : 1               :       1 :  1            : 1
-----+-----------------+---------+---------------+--------
1 0  : 0  1            :       1 :  .            :
1 1  : 0               :         :  1            : 1
-----+-----------------+---------+---------------+--------
2 0  : 0  0  1         :       1 :  .  .         :
2 1  : 0  1            :       1 :  .            :
2 2  : 0               :         :  1  1         : 2
-----+-----------------+---------+---------------+--------
3 0  : 0  0  0  1      :       1 :  .  .  .      :
3 1  : 0  1  3         :       4 :  .  .         :
3 2  : 0  1            :       1 :  .            :
3 3  : 0               :         :  2  3  1      : 6
-----+-----------------+---------+---------------+--------
4 0  : 0  0  0  0  1   :       1 :  .  .  .  .   :
4 1  : 0  1  7  6      :      14 :  .  .  .      :
4 2  : 0  4  4         :       8 :  .  .         :
4 3  : 0  1            :       1 :  .            :
4 4  : 0               :         :  6 11  6  1   : 24
-----+-----------------+---------+---------------+--------
5 0  : 0  0  0  0  0 1 :       1 :  .  .  .  . . :
5 1  : 0  1 15 25 10   :      51 :  .  .  .  .   :
5 2  : 0 14 30 10      :      54 :  .  .  .      :
5 3  : 0  8  5         :      13 :  .  .         :
5 4  : 0  1            :       1 :  .            :
5 5  : 0               :         : 24 50 35 10 1 : 120
-----+-----------------+---------+---------------+--------
		

Crossrefs

Programs

  • Maple
    b:= proc(n, t, h) option remember; expand(`if`(n=0 or h=0, x^(t*n), add(
           binomial(n-1, j-1)*x^t*b(j-1, 0, h-1)*b(n-j, t, h), j=1..n)))
        end:
    g:= (n, h)-> b(n, 1, h)-`if`(h=0, 0, b(n, 1, h-1)):
    F:= (n, h, t)-> coeff(g(n, h), x, t):
    seq(seq(seq(F(n, h, t), t=0..n-h), h=0..n), n=0..8);
  • Mathematica
    b[n_, t_, h_] := b[n, t, h] = Expand[If[n == 0 || h == 0, x^(t*n), Sum[Binomial[n-1, j-1]*x^t*b[j-1, 0, h-1]*b[n-j, t, h], {j, 1, n}]]];
    g[n_, h_] := b[n, 1, h] - If[h == 0, 0, b[n, 1, h - 1]];
    F[n_, h_, t_] := Coefficient[g[n, h], x, t];
    Table[Table[Table[F[n, h, t], {t, 0, n - h}], {h, 0, n}], {n, 0, 8}] // Flatten (* Jean-François Alcover, Mar 17 2022, after Alois P. Heinz *)

Formula

Sum_{i=0..n} F(n,i,n-i) = A000325(n).
Sum_{d=0..n} Sum_{i=0..d} F(n,i,d-i) = A000142(n).
Sum_{h=0..n} Sum_{t=0..n-h} t * F(n,h,t) = A000254(n).
Sum_{t=0..n-1} F(n,1,t) = A058692(n) = A000110(n) - 1.
F(2n,n,n) = A001791(n) for n>0.
F(2n,1,n) = A007820(n).
F(n,1,n-1) = A000217(n-1) for n>0.
F(n,n-1,1) = A057427(n).
F(n,1,2) = A000225(n-1) for n>2.
F(n,0,n) = 1 = A000012(n).
F(n,0,0) = A000007(n).

A351508 a(n) = [x^n] Product_{k=1..n} 1/(1 - k*x)^n.

Original entry on oeis.org

1, 1, 23, 1386, 162154, 31354800, 9078595483, 3682549444112, 1994756395887972, 1391788744738729470, 1216130179327397765925, 1301126343608005909401330, 1673298722590019165433540916, 2547164111922284803722749855516
Offset: 0

Views

Author

Seiichi Manyama, Feb 12 2022

Keywords

Crossrefs

Programs

  • Mathematica
    Table[SeriesCoefficient[Product[1/(1 - k*x)^n, {k,1,n}], {x,0,n}], {n,0,20}] (* Vaclav Kotesovec, Feb 18 2022 *)
  • PARI
    a(n) = polcoef(1/prod(k=1, n, 1-k*x+x*O(x^n))^n, n);

Formula

a(n) ~ exp(n + 5/3) * n^(2*n - 1/2) / (sqrt(Pi) * 2^(n + 1/2)). - Vaclav Kotesovec, Feb 18 2022
a(n) = Sum_{x_1, x_2,..., x_n >= 0 and x_1 + x_2 + ... + x_n = n} Product_{k=1..n} Stirling2(x_k + n,n). - Seiichi Manyama, May 18 2025

A213193 O.g.f.: Sum_{n>=0} (4*n+1)^(4*n+1) * exp(-(4*n+1)^4*x) * x^n / n!.

Original entry on oeis.org

1, 3124, 191757120, 49208861869440, 33030777426968816640, 45829974166034718596428800, 114009204539207742166715857223680, 462192193445890293982679086838571270144, 2851153321165202191241172917762717987236478976
Offset: 0

Views

Author

Paul D. Hanna, Mar 01 2013

Keywords

Comments

From Vaclav Kotesovec, May 13 2014: (Start)
Generally, for p>1, a(n) = 1/n! * Sum_{k=0..n} (-1)^(n-k)*binomial(n,k) * (p*k+1)^(p*n+1) = Sum_{k=0..(p-1)*n+1} p^(n+k) * binomial(p*n+1,n+k) * stirling2(n+k,n).
a(n) ~ n^(n*p-n+1/2) * p^(2*p*n+2+1/p) / (sqrt(2*Pi*(1-r)) * exp((p-1)*n) * r^(n+1/p) * (p-r)^(n*p-n+1)), where r = -LambertW(-p*exp(-p)).
(End)

Examples

			O.g.f.: A(x) = 1 + 3124*x + 191757120*x^2 + 49208861869440*x^3 +...
where
A(x) = exp(-x) + 5^5*x*exp(-5^4*x) + 9^9*exp(-9^4*x)*x^2/2! + 13^13*exp(-13^4*x)*x^3/3! + 17^17*exp(-17^4*x)*x^4/4! + 21^21*exp(-21^4*x)*x^5/5! +...
is a power series in x with integer coefficients.
		

Crossrefs

Programs

  • Mathematica
    Table[1/n!*Sum[(-1)^(n-k)*Binomial[n,k]*(4*k+1)^(4*n+1),{k,0,n}],{n,0,20}] (* Vaclav Kotesovec, May 13 2014 *)
    Table[Sum[Binomial[4*n+1,n+k]*4^(n+k)*StirlingS2[n+k,n],{k,0,3*n+1}],{n,0,20}] (* Vaclav Kotesovec, May 13 2014 *)
  • PARI
    {a(n)=polcoeff(sum(k=0, n, (4*k+1)^(4*k+1)*exp(-(4*k+1)^4*x +x*O(x^n))*x^k/k!), n)}
    for(n=0, 20, print1(a(n), ", "))
    
  • PARI
    {a(n)=(1/n!)*polcoeff(sum(k=0, n, (4*k+1)^(4*k+1)*x^k/(1+(4*k+1)^4*x +x*O(x^n))^(k+1)), n)}
    for(n=0, 20, print1(a(n), ", "))
    
  • PARI
    {a(n)=1/n!*sum(k=0, n, (-1)^(n-k)*binomial(n, k)*(4*k+1)^(4*n+1))}
    for(n=0, 20, print1(a(n), ", "))

Formula

a(n) = 1/n! * [x^n] Sum_{k>=0} (4*k+1)^(4*k+1) * x^k / (1 + (4*k+1)^4*x)^(k+1).
a(n) = 1/n! * Sum_{k=0..n} (-1)^(n-k)*binomial(n,k) * (4*k+1)^(4*n+1).
a(n) ~ n^(3*n+1/2) * 2^(16*n+9/2) / (sqrt(2*Pi*(1-r)) * exp(3*n) * r^(n+1/4) * (4-r)^(3*n+1)), where r = -LambertW(-4*exp(-4)) = 0.0793096051271136564391... . - Vaclav Kotesovec, May 13 2014

A218142 a(n) = Stirling2(n^2+n, n).

Original entry on oeis.org

1, 1, 31, 86526, 45232115901, 7713000216608565075, 666480349285726891499539272955, 41929298560838945526242744414099901692285884, 2610516895723221966171633379256064857587637240616032299710417
Offset: 0

Views

Author

Paul D. Hanna, Oct 21 2012

Keywords

Examples

			O.g.f.: A(x) = 1 + x + 31*x^2 + 86526*x^3 + 45232115901*x^4 +...
		

Crossrefs

Programs

  • Mathematica
    Table[StirlingS2[n^2+n, n],{n,0,10}] (* Vaclav Kotesovec, May 11 2014 *)
  • Maxima
    makelist(stirling2(n^2+n,n),n,0,30 ); /* Martin Ettl, Oct 21 2012 */
  • PARI
    {a(n)=polcoeff(sum(k=0,n,(k^(n+1))^k*exp(-k^(n+1)*x +x*O(x^n))*x^k/k!),n)}
    
  • PARI
    {a(n)=polcoeff(1/prod(k=1, n, 1-k*x +x*O(x^(n^2))), n^2)}
    
  • PARI
    {Stirling2(n, k)=n!*polcoeff(((exp(x+x*O(x^n))-1)^k)/k!, n)}
    {a(n) = Stirling2(n^2+n, n)}
    for(n=0, 10, print1(a(n), ", "))
    

Formula

a(n) = [x^n] Sum_{k>=0} k^((n+1)*k) * exp(-k^(n+1)*x) * x^k / k!.
a(n) = [x^(n^2)] 1 / Product_{k=1..n} (1-k*x).
a(n) ~ n^(n^2+n)/n!. - Vaclav Kotesovec, May 11 2014

A218143 a(n) = Stirling2(n*(n+1)/2, n).

Original entry on oeis.org

1, 1, 3, 90, 34105, 210766920, 26585679462804, 82892803728383735268, 7529580759157036060608585183, 22982258052528294182955639980819773510, 2672446997421818663856559987803834697952486978300, 13239043631590111512460321918828937597837325561187113535696980
Offset: 0

Views

Author

Paul D. Hanna, Oct 21 2012

Keywords

Examples

			O.g.f.: A(x) = 1 + x + 3*x^2 + 90*x^3 + 34105*x^4 + 210766920*x^5 + 26585679462804*x^6 +...
		

Crossrefs

Programs

  • Mathematica
    Table[StirlingS2[n*(n+1)/2, n],{n,0,10}] (* Vaclav Kotesovec, May 11 2014 *)
  • Maxima
    makelist(stirling2(n*(n+1)/2,n),n,0,30 ); /* Martin Ettl, Oct 21 2012 */
  • PARI
    {a(n)=polcoeff(1/prod(k=1, n, 1-k*x +x*O(x^(n*(n-1)/2))), n*(n-1)/2)}
    
  • PARI
    {Stirling2(n, k)=n!*polcoeff(((exp(x+x*O(x^n))-1)^k)/k!, n)}
    {a(n) = Stirling2(n*(n+1)/2, n)}
    for(n=0, 15, print1(a(n), ", "))
    

Formula

a(n) = [x^(n*(n-1)/2)] 1 / Product_{k=1..n} (1-k*x).
a(n) ~ n^(n*(n+1)/2)/n!. - Vaclav Kotesovec, May 11 2014

A293616 Array of generalized Eulerian number triangles read by ascending antidiagonals, with m >= 0, n >= 0 and 0 <= k <= n.

Original entry on oeis.org

1, 1, 0, 1, 1, 0, 1, 3, 0, 0, 1, 6, 0, 1, 0, 1, 10, 0, 7, 1, 0, 1, 15, 0, 25, 4, 0, 0, 1, 21, 0, 65, 10, 0, 1, 0, 1, 28, 0, 140, 20, 0, 15, 4, 0, 1, 36, 0, 266, 35, 0, 90, 30, 1, 0, 1, 45, 0, 462, 56, 0, 350, 120, 5, 0, 0, 1, 55, 0, 750, 84, 0, 1050, 350, 15, 0, 1, 0
Offset: 0

Views

Author

Peter Luschny, Oct 14 2017

Keywords

Examples

			Array starts:
m\j| 0   1  2     3    4  5       6       7    8  9      10      11      12
---|----------------------------------------------------------------------------
m=0| 1,  0, 0,    0,   0, 0,      0,      0,   0, 0,      0,      0,      0, ...
m=1| 1,  1, 0,    1,   1, 0,      1,      4,   1, 0,      1,     11,     11, ...
m=2| 1,  3, 0,    7,   4, 0,     15,     30,   5, 0,     31,    146,     91, ...
m=3| 1,  6, 0,   25,  10, 0,     90,    120,  15, 0,    301,    896,    406, ...
m=4| 1, 10, 0,   65,  20, 0,    350,    350,  35, 0,   1701,   3696,   1316, ...
m=5| 1, 15, 0,  140,  35, 0,   1050,    840,  70, 0,   6951,  11886,   3486, ...
m=6| 1, 21, 0,  266,  56, 0,   2646,   1764, 126, 0,  22827,  32172,   8022, ...
m=7| 1, 28, 0,  462,  84, 0,   5880,   3360, 210, 0,  63987,  76692,  16632, ...
m=8| 1, 36, 0,  750, 120, 0,  11880,   5940, 330, 0, 159027, 165792,  31812, ...
m=9| 1, 45, 0, 1155, 165, 0,  22275,   9900, 495, 0, 359502, 331617,  57057, ...
   A000217, A001296,A000292,A001297,A027789,A000332,A001298,A293610,A293611, ...
.
m\j| ...    13  14      15       16       17      18      19 20
---|----------------------------------------------------------------
m=0| ...,    0, 0,       0,       0,       0,      0,      0, 0, ...  [A000007]
m=1| ...,    1, 0,       1,      26,      66,     26,      1, 0, ...  [A173018]
m=2| ...,    6, 0,      63,     588,     868,    238,      7, 0, ...  [A062253]
m=3| ...,   21, 0,     966,    5376,    5586,   1176,     28, 0, ...  [A062254]
m=4| ...,   56, 0,    7770,   30660,   24570,   4200,     84, 0, ...  [A062255]
m=5| ...,  126, 0,   42525,  129780,   84630,  12180,    210, 0, ...
m=6| ...,  252, 0,  179487,  446292,  245322,  30492,    462, 0, ...
m=7| ...,  462, 0,  627396, 1315776,  625086,  68376,    924, 0, ...
m=8| ...,  792, 0, 1899612, 3444012, 1440582, 140712,   1716, 0, ...
m=9| ..., 1287, 0, 5135130, 8198190, 3063060, 270270,   3003, 0, ...
          A000389, A112494, A293612, A293613,A293614,A000579.
.
The parameter m runs over the triangles and j indexes the triangles by reading them by rows. Let T(m, n) denote the row [T(m, n, k) for 0 <= k <= n] and T(m) denote the triangle [T(m, n) for n >= 0]. Then for instance T(2) is the triangle A062253, T(4, 2) is row 2 of A062255 (which is [65, 20, 0]) and T(4, 2, 1) = 20.
		

Crossrefs

A000217(n) = T(n, 1, 0), A001296(n) = T(n, 2, 0), A000292(n) = T(n, 2, 1),
A001297(n) = T(n, 3, 0), A027789(n) = T(n, 3, 1), A000332(n) = T(n, 3, 2),
A001298(n) = T(n, 4, 0), A293610(n) = T(n, 4, 1), A293611(n) = T(n, 4, 2),
A000389(n) = T(n, 4, 3), A112494(n) = T(n, 5, 0), A293612(n) = T(n, 5, 1),
A293613(n) = T(n, 5, 2), A293614(n) = T(n, 5, 3), A000579(n) = T(n, 5, 4),
A144969(n) = T(n, 6, 0), A000580(n) = T(n, 6, 5), A000295(n) = T(1, n, 1),
A000460(n) = T(1, n, 2), A000498(n) = T(1, n, 3), A000505(n) = T(1, n, 4),
A000514(n) = T(1, n, 5), A001243(n) = T(1, n, 6), A001244(n) = T(1, n, 7),
A126646(n) = T(2, n, 0), A007820(n) = T(n, n, 0).

Programs

  • Maple
    A293616 := proc(m, n, k) option remember:
    if m = 0 then m^n elif k < 0 or k > n then 0 elif n = 0 then 1 else
    (k+m)*A293616(m,n-1,k) + (n-k)*A293616(m,n-1,k-1) + A293616(m-1,n,k) fi end:
    for m in [$0..4] do for n in [$0..6] do print(seq(A293616(m, n, k), k=0..n)) od od;
    # Sample uses:
    A001298 := n -> A293616(n, 4, 0): A293614 := n -> A293616(n, 5, 3):
    # Flatten:
    a := proc(n) local w; w := proc(k) local t, s; t := 1; s := 1;
    while t <= k do s := s + 1; t := t + s od; [s - 1, s - t + k] end:
    seq(A293616(n - k, w(k)[1], w(k)[2]), k=0..n) end: seq(a(n), n = 0..11);
  • Mathematica
    GenEulerianRow[0, n_] := Table[If[n==0 && j==0,1,0], {j,0,n}];
    GenEulerianRow[m_, n_] := If[n==0,{1},Join[CoefficientList[x^(-m) (1 - x)^(n+m)
        PolyLog[-n-m, m, x] /. Log[1-x] -> 0, x], {0}]];
    (* Sample use: *)
    A173018Row[n_] := GenEulerianRow[1, n]; Table[A173018Row[n], {n, 0, 6}]

Formula

T(m, n, k) = (k + m)*T(m, n-1, k) + (n - k)*T(m, n-1, k-1) + T(m-1, n, k) with boundary conditions T(0, n, k) = 0^n; T(m, n, k) = 0 if k < 0 or k > n; and T(m, 0, k) = 0^k.
Let h(m, n) = x^(-m)*(1 - x)^(n + m)*PolyLog(-n - m, m, x) and p(m, n) the polynomial given by the expansion of h(m, n) after replacing log(1 - x) by 0. Then T(m, n, k) is the k-th coefficient of p(m, n) for 0 <= k < n.

A293617 Array of triangles read by ascending antidiagonals, T(m, n, k) = Pochhammer(m, k) * Stirling2(n + m, k + m) with m >= 0, n >= 0 and 0 <= k <= n.

Original entry on oeis.org

1, 1, 0, 1, 1, 0, 1, 3, 1, 0, 1, 6, 2, 1, 0, 1, 10, 3, 7, 3, 0, 1, 15, 4, 25, 12, 2, 0, 1, 21, 5, 65, 30, 6, 1, 0, 1, 28, 6, 140, 60, 12, 15, 7, 0, 1, 36, 7, 266, 105, 20, 90, 50, 12, 0, 1, 45, 8, 462, 168, 30, 350, 195, 60, 6, 0, 1, 55, 9, 750, 252, 42, 1050, 560, 180, 24, 1, 0
Offset: 0

Views

Author

Peter Luschny, Oct 20 2017

Keywords

Examples

			Array starts:
m\j| 0   1  2     3       4       5       6       7       8       9      10
---|-----------------------------------------------------------------------
m=0| 1,  0, 0,    0,      0,      0,      0,      0,      0,      0,      0
m=1| 1,  1, 1,    1,      3,      2,      1,      7,     12,      6,      1
m=2| 1,  3, 2,    7,     12,      6,     15,     50,     60,     24,     31
m=3| 1,  6, 3,   25,     30,     12,     90,    195,    180,     60,    301
m=4| 1, 10, 4,   65,     60,     20,    350,    560,    420,    120,   1701
m=5| 1, 15, 5,  140,    105,     30,   1050,   1330,    840,    210,   6951
m=6| 1, 21, 6,  266,    168,     42,   2646,   2772,   1512,    336,  22827
m=7| 1, 28, 7,  462,    252,     56,   5880,   5250,   2520,    504,  63987
m=8| 1, 36, 8,  750,    360,     72,  11880,   9240,   3960,    720, 159027
m=9| 1, 45, 9, 1155,    495,     90,  22275,  15345,   5940,    990, 359502
   A000217, A001296,A027480,A002378,A001297,A293475,A033486,A007531,A001298
.
m\j| ...      11      12      13      14
---|-----------------------------------------
m=0| ...,      0,      0,      0,      0, ... [A000007]
m=1| ...,     15,     50,     60,     24, ... [A028246]
m=2| ...,    180,    390,    360,    120, ... [A053440]
m=3| ...,   1050,   1680,   1260,    360, ... [A294032]
m=4| ...,   4200,   5320,   3360,    840, ...
m=5| ...,  13230,  13860,   7560,   1680, ...
m=6| ...,  35280,  31500,  15120,   3024, ...
m=7| ...,  83160,  64680,  27720,   5040, ...
m=8| ..., 178200, 122760,  47520,   7920, ...
m=9| ..., 353925, 218790,  77220,  11880, ...
         A293476,A293608,A293615,A052762, ...
.
The parameter m runs over the triangles and j indexes the triangles by reading them by rows. Let T(m, n) denote the row [T(m, n, k) for 0 <= k <= n] and T(m) denote the triangle [T(m, n) for n >= 0]. Then for instance T(2) is the triangle A053440, T(3, 2) is row 2 of A294032 (which is [25, 30, 12]) and T(3, 2, 1) = 30.
.
Remark: To adapt the sequences A028246 and A053440 to our enumeration use the exponential generating functions exp(x)/(1 - y*(exp(x) - 1)) and exp(x)*(2*exp(x) - y*exp(2*x) + 2*y*exp(x) - 1 - y)/(1 - y*(exp(x) - 1))^2 instead of those indicated in their respective entries.
		

Crossrefs

A000217(n) = T(n, 1, 0), A001296(n) = T(n, 2, 0), A027480(n) = T(n, 2, 1),
A002378(n) = T(n, 2, 2), A001297(n) = T(n, 3, 0), A293475(n) = T(n, 3, 1),
A033486(n) = T(n, 3, 2), A007531(n) = T(n, 3, 3), A001298(n) = T(n, 4, 0),
A293476(n) = T(n, 4, 1), A293608(n) = T(n, 4, 2), A293615(n) = T(n, 4, 3),
A052762(n) = T(n, 4, 4), A052787(n) = T(n, 5, 5), A000225(n) = T(1, n, 1),
A028243(n) = T(1, n, 2), A028244(n) = T(1, n, 3), A028245(n) = T(1, n, 4),
A032180(n) = T(1, n, 5), A228909(n) = T(1, n, 6), A228910(n) = T(1, n, 7),
A000225(n) = T(2, n, 0), A007820(n) = T(n, n, 0).
A028246(n,k) = T(1, n, k), A053440(n,k) = T(2, n, k), A294032(n,k) = T(3, n, k),
A293926(n,k) = T(n, n, k), A124320(n,k) = T(n, k, k), A156991(n,k) = T(k, n, n).
Cf. A293616.

Programs

  • Maple
    A293617 := proc(m, n, k) option remember:
    if m = 0 then 0^n elif k < 0 or k > n then 0 elif n = 0 then 1 else
    (k+m)*A293617(m,n-1,k) + k*A293617(m,n-1,k-1) + A293617(m-1,n,k) fi end:
    for m in [$0..4] do for n in [$0..6] do print(seq(A293617(m, n, k), k=0..n)) od od;
    # Sample uses:
    A027480 := n -> A293617(n, 2, 1): A293608 := n -> A293617(n, 4, 2):
    # Flatten:
    a := proc(n) local w; w := proc(k) local t, s; t := 1; s := 1;
    while t <= k do s := s + 1; t := t + s od; [s - 1, s - t + k] end:
    seq(A293617(n - k, w(k)[1], w(k)[2]), k=0..n) end: seq(a(n), n = 0..11);
  • Mathematica
    T[m_, n_, k_] := Pochhammer[m, k] StirlingS2[n + m, k + m];
    For[m = 0, m < 7, m++, Print[Table[T[m, n, k], {n,0,6}, {k,0,n}]]]
    A293617Row[m_, n_] := Table[T[m, n, k], {k,0,n}];
    (* Sample use: *)
    A293926Row[n_] := A293617Row[n, n];

Formula

T(m,n,k) = (k + m)*T(m, n-1, k) + k*T(m, n-1, k-1) + T(m-1, n, k) with boundary conditions T(0, n, k) = 0^n; T(m, n, k) = 0 if k<0 or k>n; and T(m, 0, k) = 0^k.
T(m,n,k) = Pochhammer(m, k)*binomial(n + m, k + m)*NorlundPolynomial(n - k, -k - m).
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