A107718 Column 1 of triangle A107717.

1, 6, 57, 723, 11361, 212151, 4584081, 112480887, 3090105921, 93988998183, 3136338148017, 113945190405303, 4477940877230625, 189296643095867847, 8565988634172222609, 413169192012610306263, 21161884092470464784385

Offset: 0

Author

Paul D. Hanna, May 30 2005

Keywords

• nonn

Comments

Equals one-half of column 0 of A107719 shift 1 place left.

Crossrefs

Cf. A107717, A107719.

Programs

PARI

{a(n)=if(n<0,0,(matrix(n+2,n+2,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)[n+2,2])}