A124528 a(n) = Sum_{k=0..n} 2^k*A124526(n,k) for n>=0.

1, 1, 3, 8, 26, 94, 377, 1639, 7623, 38034, 199338, 1111816, 6442481, 39478219, 249507483, 1659172454, 11321526022, 80944313164, 591617080305, 4514822914133, 35120998653271, 284407875530728, 2342407874087454

Offset: 0

Author

Paul D. Hanna, Nov 08 2006

Keywords

• nonn

Crossrefs

Cf. A124526, A124527, A124529.

Programs

PARI

{a(n)=sum(k=0,n\2,2^k*(n\2)!*((n+1)\2)!*polcoeff(polcoeff(exp((1+y)*(exp(x+x*O(x^n))-1)),n\2),k) *polcoeff(polcoeff(exp((1+y)*(exp(x+x*O(x^n))-1)),(n+1)\2),k))}