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A270497 Sum of the sizes of the fifth blocks in all set partitions of {1,2,...,n}. 2
1, 17, 184, 1641, 13276, 102244, 770989, 5795889, 43967302, 339403001, 2681449074, 21763977864, 181900742989, 1567473197429, 13932812925824, 127738400615689, 1207445992487256, 11759938209394472, 117926100082535985, 1216563820893322317, 12901060857158377838 (list; graph; refs; listen; history; text; internal format)
OFFSET

5,2

LINKS

Alois P. Heinz, Table of n, a(n) for n = 5..575

Wikipedia, Partition of a set

MAPLE

b:= proc(n, m) option remember; `if`(n=0, [1, 0],

      add((p->`if`(j<6, [p[1], p[2]+p[1]*x^j], p))(

       b(n-1, max(m, j))), j=1..m+1))

    end:

a:= n-> coeff(b(n, 0)[2], x, 5):

seq(a(n), n=5..30);

MATHEMATICA

b[n_, m_] := b[n, m] = If[n == 0, {1, 0}, Sum[Function[p, If[j < 6, {p[[1]], p[[2]] + p[[1]]*x^j}, p]][b[n - 1, Max[m, j]]], {j, 1, m + 1}]];

a[n_] := Coefficient[b[n, 0][[2]], x, 5];

Table[a[n], {n, 5, 30}] (* Jean-Fran├žois Alcover, May 27 2018, translated from Maple *)

CROSSREFS

Column p=5 of A270236.

Sequence in context: A167578 A181401 A243419 * A025958 A199674 A022741

Adjacent sequences:  A270494 A270495 A270496 * A270498 A270499 A270500

KEYWORD

nonn

AUTHOR

Alois P. Heinz, Mar 18 2016

STATUS

approved

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Last modified October 20 05:49 EDT 2019. Contains 328247 sequences. (Running on oeis4.)