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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A325138 a(n) = Sum_{k=0..n} Sum_{j=0..n-k} binomial(j+k, k)*|Stirling1(n, j+k)|*(k+1)^j.

Original entry on oeis.org

1, 2, 8, 45, 320, 2730, 27054, 304584, 3832688, 53233272, 808045560, 13297113720, 235635543912, 4471304008704, 90415029604704, 1940195561267880, 44021278940004480, 1052672670160355520, 26454200168941936704, 696874344218429604480, 19198703924579071278720
Offset: 0

Views

Author

Peter Luschny, Apr 13 2019

Keywords

Crossrefs

Row sums of A325137.

Programs

  • PARI
    a(n) = sum(k=0, n, sum(j=0, n-k, binomial(j+k, k)*abs(stirling(n, j+k, 1))*(k+1)^j)); \\ Michel Marcus, Apr 13 2019

A325139 Triangle T(n, k) = [t^n] Gamma(n + k + m + t)/Gamma(k + m + t) for m = 2 and 0 <= k <= n, read by rows.

Original entry on oeis.org

1, 2, 1, 6, 7, 1, 24, 47, 15, 1, 120, 342, 179, 26, 1, 720, 2754, 2070, 485, 40, 1, 5040, 24552, 24574, 8175, 1075, 57, 1, 40320, 241128, 305956, 134449, 24885, 2086, 77, 1, 362880, 2592720, 4028156, 2231012, 541849, 63504, 3682, 100, 1
Offset: 0

Views

Author

Peter Luschny, Apr 15 2019

Keywords

Examples

			0:        1;
1:        2,        1;
2:        6,        7,        1;
3:       24,       47,       15,        1;
4:      120,      342,      179,       26,        1;
5:      720,     2754,     2070,      485,       40,       1;
6:     5040,    24552,    24574,     8175,     1075,      57,      1;
7:    40320,   241128,   305956,   134449,    24885,    2086,     77,    1;
8:   362880,  2592720,  4028156,  2231012,   541849,   63504,   3682,  100,   1;
9:  3628800, 30334320, 56231712, 37972304, 11563650, 1768809, 142632, 6054, 126, 1;
A:  A000142,  A001711,  A001717,  A001723, ...
		

Crossrefs

Row sums are A325140.
Columns are: A000142, A001711, A001717, A001723.
Family: A307419 (m=0), A325137 (m=1), this sequence (m=2).

Programs

  • Maple
    T := (n, k) -> add(binomial(j+k, k)*(k+2)^j*abs(Stirling1(n, j+k)), j=0..n-k):
    seq(seq(T(n, k), k=0..n), n=0..8);
    # Note that for n > 16 Maple fails (at least in some versions) to compute the
    # terms properly. Inserting 'simplify' or numerical evaluation might help.
    A325139Row := proc(n) local ogf, ser; ogf := (n, k) -> GAMMA(n+k+2+x)/GAMMA(k+2+x);
    ser := (n, k) -> series(ogf(n,k), x, k+2); seq(coeff(ser(n,k), x, k), k=0..n) end:
    seq(A325139Row(n), n=0..9);

Formula

T(n, k) = Sum_{j=0..n-k} binomial(j+k, k)*abs(Stirling1(n, j+k))*(k+2)^j.
Showing 1-2 of 2 results.