OFFSET
0,4
LINKS
Seiichi Manyama, Table of n, a(n) for n = 0..339
MATHEMATICA
a[0] = 1; a[n_] := Sum[(-2)^(n - k) * Binomial[n, k] * Binomial[n + (n - 1)*k, k - 1], {k, 1, n}] / n; Array[a, 20, 0] (* Amiram Eldar, Aug 01 2020 *)
PROG
(PARI) {a(n) = if(n==0, 1, sum(k=1, n, (-2)^(n-k)*binomial(n, k)*binomial(n+(n-1)*k, k-1))/n)}
CROSSREFS
KEYWORD
nonn
AUTHOR
Seiichi Manyama, Aug 01 2020
STATUS
approved