A270761 Total sum of the sizes of all blocks with maximal element 7 in all set partitions of {1,2,...,n}.

2095, 7307, 29278, 131007, 643401, 3426532, 19610565, 119762455, 776018428, 5310053713, 38218929257, 288361428110, 2274040468083, 18695782169431, 159876844021430, 1419201089763907, 13053572286094533, 124202259586825404, 1220668798203165121

Offset: 7

Author

Alois P. Heinz, Mar 22 2016

Keywords

• nonn

Links

• Alois P. Heinz, Table of n, a(n) for n = 7..577
• Wikipedia, Partition of a set

Crossrefs

Column k=7 of A270701.

A diagonal of A270702.

Programs

Mathematica

b[n_, m_, t_] := b[n, m, t] = If[n == 0, {1, 0}, Sum[If[t == 1 && j != m + 1, 0, Function[p, p + If[j == -t || t == 1 && j == m + 1, {0, p[[1]]}, 0]][b[n - 1, Max[m, j], If[t == 1 && j == m + 1, -j, If[t < 0, t, If[t > 0, t - 1, 0]]]]]], {j, 1, m + 1}]];
a[n_] := b[n, 0, Max[0, 1 + n - 7]][[2]];
Array[a, 24, 7] (* Jean-François Alcover, May 26 2018, from Maple code for A270701 *)