A107720 Column 0 of triangle A107719.

1, 1, 5, 43, 509, 7579, 135341, 2813851, 66733853, 1778159275, 52604224205, 1711276244731, 60729274013309, 2335153500391627, 96727188777453869, 4294441686826824091, 203456100846249179357, 10245810557884742785387

Offset

0,3

Links

Table of n, a(n) for n=0..17.

Prog

(PARI) {a(n)=local(E, L, M=matrix(n+1, n+1, m, j, if(m>=j, if(m==j, 1, if(m==j+1, -3*j, -polcoeff(1-(1+sum(c=1, m-j, prod(i=0, c-1, 3*i+1)*x^c)+x*O(x^(m-j)))^-1, m-j); ))))^-1); L=matrix(#M, #M, r, c, if(r>=c, sum(i=1, #M, (-1)^(i-1)*(M-M^0)^i/i)[r, c])); E=matrix(#L, #L, r, c, if(r>=c, sum(i=0, #L, L^i/3^i/i!)[r, c])); if(n<0, 0, E[n+1, 1])}

Crossrefs

Cf. A107717, A107719.

Sequence in context: A093620 A231277 A188365 * A362188 A299425 A360618

Adjacent sequences: A107717 A107718 A107719 * A107721 A107722 A107723

Keyword

nonn

Author

Paul D. Hanna, May 30 2005

Status

approved