A228903 Second diagonal of triangle A228902.

1, 3, 45, 2905, 411500, 100545716, 37614371968, 19977489354808, 14291976911388733, 13248449270832615473, 15445843697030022753539, 22118947642938636936616739, 38166279965353127309979185861, 78098472647949324804924786089941, 186993874842690500015923551395259661

Offset: 1

Author

Paul D. Hanna, Sep 07 2013

Keywords

• nonn

Comments

Triangle A228902 is defined by g.f.: exp( Sum_{n>=1} x^n/n * Sum_{k=0..n} binomial(n^2, k^2) * y^k ).

Crossrefs

Cf. A228902.

Programs

PARI

{a(n)=polcoeff(polcoeff(exp(sum(m=1, n, x^m/m*sum(j=0, m, binomial(m^2, j^2)*y^j))+x*O(x^n)), n, x), n-1, y)}
for(n=1, 20, print1(a(n), ", "))