OFFSET
0,7
LINKS
Alois P. Heinz, Table of n, a(n) for n = 0..2000
FORMULA
G.f.: x + x^2 + x^3 * Product_{n>=1} (1 + x^n)^a(n). - Ilya Gutkovskiy, May 09 2019
MAPLE
b:= proc(n, i) option remember; `if`(n=0, 1, `if`(i<1, 0,
add(binomial(a(i), j)*b(n-i*j, i-1), j=0..n/i)))
end:
a:= n-> (k-> `if`(n<k, signum(n), b(n-k$2)))(3):
seq(a(n), n=0..42);
CROSSREFS
KEYWORD
nonn,eigen
AUTHOR
Alois P. Heinz, Jun 23 2018
STATUS
approved