OFFSET
0,4
LINKS
Alois P. Heinz, Table of n, a(n) for n = 0..10000
FORMULA
E.g.f. satisfies A(x) = Product_{i>=1} (1-x^(a(i)*(i+1)))/(1-x^i).
MAPLE
b:= proc(n, i) option remember; `if`(n=0, 1, `if`(i<1, 0,
add(b(n-i*j, i-1), j=0..min(n/i, a(i)))))
end:
a:= n-> `if`(n=0, 0, 1)+b(n, n-1):
seq(a(n), n=0..70); # Alois P. Heinz, Jun 12 2018
MATHEMATICA
b[n_, i_] := b[n, i] = If[n == 0, 1, If[i < 1, 0, Sum[b[n - i j, i - 1], {j, 0, Min[n/i, a[i]]}]]];
a[n_] := If[n == 0, 0, 1] + b[n, n - 1];
a /@ Range[0, 70] (* Jean-François Alcover, Nov 23 2020, after Alois P. Heinz *)
CROSSREFS
KEYWORD
nonn,eigen
AUTHOR
Christian G. Bower, Dec 19 1999
STATUS
approved