OFFSET
6,1
LINKS
Alois P. Heinz, Table of n, a(n) for n = 6..1000
MAPLE
g:= proc(n, i) option remember; convert(series(`if`(n=0, 1,
`if`(i<1, 0, add(g(n-i*j, i-1)*(ithprime(i)*x)^j
, j=0..min(1, n/i)))), x, 4), polynom)
end:
a:= n-> coeff(g(n$2), x, 3):
seq(a(n), n=6..60);
MATHEMATICA
g[n_, i_] := g[n, i] = If[n == 0, 1, If[i < 1, 0, Sum[g[n - i j, i - 1] (Prime[i] x)^j, {j, 0, Min[1, n/i]}]]];
a[n_] := Coefficient[g[n, n], x, 3];
a /@ Range[6, 60] (* Jean-François Alcover, Dec 11 2020, after Alois P. Heinz *)
CROSSREFS
KEYWORD
nonn
AUTHOR
Alois P. Heinz, May 27 2015
STATUS
approved