OFFSET
1,4
LINKS
Seiichi Manyama, Table of n, a(n) for n = 1..448
MATHEMATICA
nmax = 50; A000593 = Table[Sum[Mod[d, 2] d, {d, Divisors[n]}], {n, 1, nmax}]; Table[n!/6 * Sum[Sum[Sum[If[i + j + k == n, A000593[[i]] * A000593[[j]] * A000593[[k]] / (i*j*k), 0], {k, 1, n}], {j, 1, n}], {i, 1, n}], {n, 1, nmax}] (* Vaclav Kotesovec, Nov 09 2020 *)
PROG
(PARI) {a(n) = my(t='t); n!*polcoef(polcoef(prod(k=1, n, (1+x^k+x*O(x^n))^t), n), 3)}
CROSSREFS
KEYWORD
nonn
AUTHOR
Seiichi Manyama, Nov 09 2020
STATUS
approved