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 1-2 of 2 results.

A091028 Alternating row sums of array A090440 (generalized Stirling2 array (4,3)).

Original entry on oeis.org

1, -1, -299, 40751, 5067841, -7323445921, -999631061099, 8071239253153439, 3226932423143680609, -35637793578511857426241, -56681720635442893862661899, 428341845237867375193339807439, 2249822227541602344980346463546081
Offset: 1

Views

Author

Wolfdieter Lang, Dec 23 2003

Keywords

Crossrefs

Cf. A070531 (row sums of A090440).

Formula

a(n)=-sum(((-1)^k)*A090440(n, k), k=3..3*n), n>=1.

A070531 Generalized Bell numbers B_{4,3}.

Original entry on oeis.org

1, 73, 16333, 8030353, 7209986401, 10541813012041, 23227377813664333, 72925401604382826913, 312727862321385812968033, 1772004571987390827615327241, 12917715377912025572750844722221, 118521774439119390334062953438350513, 1343761301099219856651740487814621053313
Offset: 1

Views

Author

Karol A. Penson, May 02 2002

Keywords

Crossrefs

Cf. A091028 (alternating row sums of A090440).

Programs

Formula

In Maple notation, a(n) = (1/12)*n!*(n+1)!*(n+2)!*hypergeom([n+1, n+2, n+3], [2, 3, 4], 1)/exp(1).
a(n) = Sum_{k=3..3*n} A090440(n, k) = (Sum_{k>=3} (1/k!)*Product_{j=1..n} fallfac(k+(j-1)*(4-3), 3))/exp(1), n>=1. From eq.(9) of the Blasiak et al. reference with r=4, s=3. fallfac(n, m) := A008279(n, m) (falling factorials triangle). a(0) := 1 may be added.

Extensions

Edited by Wolfdieter Lang, Dec 23 2003
Showing 1-2 of 2 results.