A132617 Column 1 of triangle A132615.

1, 1, 3, 25, 378, 8460, 252087, 9392890, 420142350, 21927528948, 1307723670020, 87712176219801, 6534001434836758, 535159878432210000, 47792303301224799288, 4621416976280491118910, 481020078381722064175750

Offset: 0

Author

Paul D. Hanna, Aug 24 2007

Keywords

• nonn

Comments

Triangle T=A132615 is generated by odd matrix powers of itself such that row n+1 of T = row n of T^(2n-1) with appended '1' for n>=0 with T(0,0)=1.

Crossrefs

Cf. A132615 (triangle); other columns: A132616, A132618; A132619.

Programs

PARI

{a(n)=local(A=vector(n+1), p); A[1]=1; for(j=1, n-1, p=n*(n-1)-(n-j)*(n-j-1); A=Vec((Polrev(A)+x*O(x^p))/(1-x))); A=Vec((Polrev(A)+x*O(x^p))/(1-x)); A[p+1]}

Formula

a(n) is divisible by 2n-1 for n>0; a(n)/(2n-1) = A132619(n).