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.

A264430 Triangle read by rows, Bell transform of second order Bell numbers (A187761).

Original entry on oeis.org

1, 0, 1, 0, 1, 1, 0, 2, 3, 1, 0, 6, 11, 6, 1, 0, 23, 50, 35, 10, 1, 0, 106, 268, 225, 85, 15, 1, 0, 568, 1645, 1603, 735, 175, 21, 1, 0, 3459, 11348, 12572, 6713, 1960, 322, 28, 1, 0, 23544, 86775, 107738, 65352, 22323, 4536, 546, 36, 1, 0, 176850, 727629, 1001895, 678980, 263865, 63021, 9450, 870, 45, 1
Offset: 0

Views

Author

Peter Luschny, Nov 13 2015

Keywords

Examples

			Triangle starts:
[1]
[0,    1]
[0,    1,     1]
[0,    2,     3,     1]
[0,    6,    11,     6,    1]
[0,   23,    50,    35,   10,    1]
[0,  106,   268,   225,   85,   15,   1]
[0,  568,  1645,  1603,  735,  175,  21,  1]
[0, 3459, 11348, 12572, 6713, 1960, 322, 28, 1]
		

Crossrefs

Programs

  • Mathematica
    nmax = 10;
    A187761[n_] := Sum[BellY[n, k, BellB /@ Range[0, n-1]], {k, 0, n}];
    Table[BellY[n, k, A187761 /@ Range[0, nmax]], {n, 0, nmax}, {k, 0, n}] // Flatten (* Jean-François Alcover, Jul 10 2019 *)
  • Sage
    # uses[bell_transform from A264428]
    def A264430_triangle(dim):
        uno = [1]*dim
        bell_numbers = [sum(bell_transform(n, uno)) for n in range(dim)]
        bell_number_2 = [sum(bell_transform(n, bell_numbers)) for n in range(dim)]
        for n in range(dim): print(bell_transform(n, bell_number_2))
    A264430_triangle(10)