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.

A325146 A(n, k) = Stirling2(n + k, k)*A053657(n)*k!/(n + k)!, array read by ascending antidiagonals for n >= 0 and k >= 0.

Original entry on oeis.org

1, 0, 1, 0, 1, 1, 0, 4, 2, 1, 0, 2, 14, 3, 1, 0, 48, 12, 30, 4, 1, 0, 16, 496, 36, 52, 5, 1, 0, 576, 288, 2064, 80, 80, 6, 1, 0, 144, 18288, 1656, 5832, 150, 114, 7, 1, 0, 3840, 8160, 145200, 5920, 13240, 252, 154, 8, 1
Offset: 0

Views

Author

Peter Luschny, May 22 2019

Keywords

Examples

			[0] 1,   1,     1,      1,      1,       1,       1,        1, ... A000012
[1] 0,   1,     2,      3,      4,       5,       6,        7, ... A001477
[2] 0,   4,    14,     30,     52,      80,     114,      154, ... A049451
[3] 0,   2,    12,     36,     80,     150,     252,      392, ... A011379
[4] 0,  48,   496,   2064,   5832,   13240,   26088,    46536, ...
[5] 0,  16,   288,   1656,   5920,   16200,   37296,    76048, ...
[6] 0, 576, 18288, 145200, 654816, 2153280, 5775936, 13429248, ...
     A163176
		

Crossrefs

Rows include A001477, A049451, A011379. Columns include A163176.
Cf. A053657.

Programs

  • Maple
    A := (n, k) -> Stirling2(n + k, k)*A053657(n)*k!/(n + k)!:
    seq(seq(A(n - k, k), k=0..n), n=0..10);
  • Mathematica
    a053657[n_] := Product[p^Sum[Floor[(n-1) / ((p-1) p^k)], {k, 0, n}], {p, Prime[Range[n]]}];
    A[n_, k_] := StirlingS2[n+k, k] a053657[n+1] k! / (n+k)!;
    Table[A[n-k, k], {n, 0, 10}, {k, 0, n}] // Flatten (* Jean-François Alcover, Jul 21 2019 *)