OFFSET
13,1
LINKS
Joerg Arndt and Alois P. Heinz, Table of n, a(n) for n = 13..100
MATHEMATICA
b[n_, i_, t_] := b[n, i, t] = If[n < 1, 1, Expand[Sum[ If[j < i, x, 1] *b[n - 1, j, t + If[j == i, 1, 0]], {j, 0, t + 1}]]]; a[n_] := Coefficient[b[n - 1, 0, 0], x, 7]; Table[a[n], {n, 13, 40}] (* Jean-François Alcover, Feb 09 2015, after A242352 *)
CROSSREFS
KEYWORD
nonn
AUTHOR
Joerg Arndt and Alois P. Heinz, Jun 05 2014
STATUS
approved