OFFSET
1,3
COMMENTS
G.f.: Sum_{n>=0} Sum_{d|n} ((x^(n+1)-x)^d-(x^n-x)^d)/(x-1)^d.
LINKS
Alois P. Heinz, Table of n, a(n) for n = 1..250
MAPLE
b:= proc(n, t, g) option remember; `if` (n=0, `if` (irem(g, t)=0, 1, 0), add (b(n-i, t+1, max(i, g)), i=1..n)) end: a:= n-> b(n, 0, 0): seq (a(n), n=1..40); # Alois P. Heinz, Dec 15 2009
MATHEMATICA
b[n_, t_, g_] := b[n, t, g] = If[n == 0, If[Mod[g, t] == 0, 1, 0],
Sum[b[n - i, t + 1, Max[i, g]], {i, 1, n}]];
a[n_] := b[n, 0, 0];
Table [a[n], {n, 1, 40}] (* Jean-François Alcover, Jul 11 2021, after Alois P. Heinz *)
CROSSREFS
KEYWORD
easy,nonn
AUTHOR
Vladeta Jovovic, Dec 13 2009
EXTENSIONS
More terms from Alois P. Heinz, Dec 15 2009
STATUS
approved