A105617 Column 2 of triangle A105615.

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

Offset

0,2

Links

Table of n, a(n) for n=0..16.

Prog

(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])}

Crossrefs

Cf. A105615.

Sequence in context: A355421 A005416 A300989 * A297926 A094072 A361193

Adjacent sequences: A105614 A105615 A105616 * A105618 A105619 A105620

Keyword

nonn

Author

Paul D. Hanna, Apr 16 2005

Status

approved