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 1-3 of 3 results.

A211210 a(n) = Sum_{k=0..n} binomial(n, k)*|S1(n, k)|.

Original entry on oeis.org

1, 1, 3, 16, 115, 1021, 10696, 128472, 1734447, 25937683, 424852351, 7554471156, 144767131444, 2971727661124, 65013102375404, 1509186299410896, 37032678328740751, 957376811266995031, 25999194631060525009, 739741591417352081464, 22000132609456951524051
Offset: 0

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Author

Olivier Gérard, Oct 23 2012

Keywords

Comments

Binomial convolution of the unsigned Stirling numbers of the first kind.
Row sums of triangle A187555.

Crossrefs

Cf. A317274 (signed S1), A187555, A134090, A211211.
Cf. A122455 (second kind), A271702, A134094, A343841 (second kind inverse).

Programs

  • Mathematica
    Table[Sum[Binomial[n, k] Abs[StirlingS1[n, k]], {k, 0, n}], {n, 0, 20}]
  • PARI
    a(n) = sum(k=0, n, binomial(n, k)*abs(stirling(n, k, 1))); \\ Michel Marcus, May 10 2021

A317274 a(n) = Sum_{k=0..n} binomial(n,k)*Stirling1(n,k).

Original entry on oeis.org

1, 1, -1, -2, 19, -79, 76, 2640, -36945, 329371, -1861949, -4438774, 355714228, -7292531180, 109844527612, -1277006731104, 8181112825231, 124379387459175, -6806984421310187, 191750786928500050, -4289244423048443149, 80163499107525756105, -1146313133241947091420, 5494990440819210736560
Offset: 0

Views

Author

Ilya Gutkovskiy, Jul 25 2018

Keywords

Comments

Binomial convolution of the signed Stirling numbers of the first kind.

Crossrefs

Programs

  • Mathematica
    Table[Sum[Binomial[n, k] StirlingS1[n, k], {k, 0, n}], {n, 0, 23}]
  • PARI
    a(n) = sum(k=0, n, binomial(n, k)*stirling(n, k, 1)); \\ Michel Marcus, Aug 07 2019

A271700 Triangle read by rows, T(n,k) = Sum_{j=0..n} (-1)^(n-j)*C(-j-1,-n-1)*S1(k,j), S1 the Stirling cycle numbers A132393, for n>=0 and 0<=k<=n.

Original entry on oeis.org

1, 1, 1, 1, 2, 3, 1, 3, 6, 16, 1, 4, 10, 30, 115, 1, 5, 15, 50, 205, 1021, 1, 6, 21, 77, 336, 1750, 10696, 1, 7, 28, 112, 518, 2814, 17766, 128472, 1, 8, 36, 156, 762, 4308, 28050, 207942, 1734447, 1, 9, 45, 210, 1080, 6342, 42528, 322860, 2746815, 25937683
Offset: 0

Views

Author

Peter Luschny, Apr 14 2016

Keywords

Examples

			Triangle starts:
[1]
[1, 1]
[1, 2, 3]
[1, 3, 6,  16]
[1, 4, 10, 30,  115]
[1, 5, 15, 50,  205, 1021]
[1, 6, 21, 77,  336, 1750, 10696]
[1, 7, 28, 112, 518, 2814, 17766, 128472]
		

Crossrefs

A000027 (col. 1), A000217, A161680 (col. 2), A005581 (col. 3), A211210 (diag. n,n), A211211 (diag. n,n-1).

Programs

  • Maple
    T := (n,k) -> add(abs(Stirling1(k,j))*binomial(-j-1,-n-1)*(-1)^(n-j),j=0..n);
    seq(seq(T(n,k), k=0..n), n=0..9);
  • Mathematica
    Flatten[Table[Sum[(-1)^(n-j)Binomial[-j-1,-n-1] Abs[StirlingS1[k,j]],{j,0,n}], {n,0,9},{k,0,n}]]
Showing 1-3 of 3 results.