OFFSET
0,4
LINKS
Alois P. Heinz, Table of n, a(n) for n = 0..10000 (terms n=1..165 from Robert G. Wilson v)
MAPLE
with(numtheory):
b:= proc(n, t) option remember; `if`(n=0, 1, add(add(`if`(
(d+t)::odd, d, 0), d=divisors(j))*b(n-j, t), j=1..n)/n)
end:
a:= n-> b(n, 0) -b(n, 1):
seq(a(n), n=0..80); # Alois P. Heinz, Feb 24 2017
MATHEMATICA
f[n_] := Length[ IntegerPartitions[n, All, 2Range[n] -1]] - Length[ IntegerPartitions[n, All, 2 Range[n]]]; Array[f, 60]
(* Second program: *)
b[n_, t_] := b[n, t] = If[n == 0, 1, Sum[Sum[If[
OddQ[d+t], d, 0], {d, Divisors[j]}]*b[n-j, t], {j, 1, n}]/n];
a[n_] := b[n, 0] - b[n, 1];
a /@ Range[0, 80] (* Jean-François Alcover, Jun 06 2021, after Alois P. Heinz *)
CROSSREFS
KEYWORD
nonn
AUTHOR
Robert G. Wilson v, Feb 24 2017
STATUS
approved