OFFSET
4,2
LINKS
Alois P. Heinz, Table of n, a(n) for n = 4..1663
MAPLE
b:= proc(n, i, k) option remember; `if`(n=0 or i<2, add(
Stirling2(n, j), j=0..k), add(b(n-i*j, i-1, k), j=0..n/i))
end:
a:= n-> (k-> b(n$2, k)-b(n$2, k-1))(4):
seq(a(n), n=4..35);
MATHEMATICA
b[n_, i_, k_] := b[n, i, k] = If[n == 0 || i < 2, Sum[StirlingS2[n, j], {j, 0, k}], Sum[b[n - i*j, i - 1, k], {j, 0, n/i}]];
a[n_] := With[{k = 4}, b[n, n, k] - b[n, n, k-1]];
a /@ Range[4, 35] (* Jean-François Alcover, Dec 17 2020, after Alois P. Heinz *)
CROSSREFS
KEYWORD
nonn
AUTHOR
Alois P. Heinz, Oct 21 2018
STATUS
approved