OFFSET
6,1
LINKS
Alois P. Heinz, Table of n, a(n) for n = 6..900
MAPLE
b:= proc(n, v) option remember; `if`(n=0, [1, 0$3],
add(`if`(v in [0, i], b(n-i, `if`(i<=n-i, i, -1)),
[0, b(n-i, `if`(i<=n-i, i, -1))[1..3][]]), i=1..n))
end:
a:= n-> b(n, 0)[4]:
seq(a(n), n=6..60);
MATHEMATICA
b[n_, v_] := b[n, v] = If[n == 0, 1, Expand[Sum[b[n - i, i]*
If[v == 0 || v == i, 1, x], {i, n}]]];
a[n_] := Coefficient[b[n, 0], x, 3];
Table[a[n], {n, 6, 60}] (* Jean-François Alcover, Aug 29 2021, after A238279 Maple code *)
CROSSREFS
KEYWORD
nonn
AUTHOR
Joerg Arndt and Alois P. Heinz, Jul 04 2014
STATUS
approved