A105617 Column 2 of triangle A105615.

1, 6, 50, 522, 6498, 93666, 1532970, 28079082, 569212578, 12655466946, 306280630890, 8017054975242, 225716319717858, 6802519195684386, 218521006115328810, 7454198349649868202, 269114811307118424738

Offset: 0

Author

Paul D. Hanna, Apr 16 2005

Keywords

• nonn

Crossrefs

Cf. A105615.

Programs

PARI

{a(n)=if(n<0,0,(matrix(n+3,n+3,m,j,if(m>=j,if(m==j,1,if(m==j+1,-2*j, polcoeff(1/sum(i=0,m-j,(2*i)!/i!/2^i*x^i)+O(x^m),m-j) ))))^-1)[n+3,3])}