OFFSET
0,2
LINKS
Seiichi Manyama, Table of n, a(n) for n = 0..100
PROG
(PARI) {a(n) = my(t='t); (2*n)!*polcoef(polcoef(prod(k=1, 2*n, (1-x^k+x*O(x^(2*n)))^(-1-t)), 2*n), n)}
(PARI) {a(n) = my(t='t); if(n==0, 1, (2*n)!*polcoef(polcoef(exp(sum(k=1, 2*n, (1+t)*sigma(k)*(x^k+x*O(x^(2*n)))/k)), 2*n), n))}
CROSSREFS
KEYWORD
nonn
AUTHOR
Seiichi Manyama, Nov 07 2020
STATUS
approved