A107725 Column 0 of A107724, which is the matrix logarithm of triangle A107719.

0, 1, 4, 31, 343, 4855, 83209, 1670743, 38436673, 996825703, 28778874481, 915636860023, 31837734460129, 1201360385000071, 48899006799783889, 2135779996980897175, 99646497213608842561, 4946194601237466540967

Offset

0,3

Links

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

Prog

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

Crossrefs

Cf. A107717, A107719, A107724.

Sequence in context: A076280 A141005 A122400 * A145160 A129271 A136728

Adjacent sequences: A107722 A107723 A107724 * A107726 A107727 A107728

Keyword

nonn

Author

Paul D. Hanna, May 30 2005

Status

approved