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A132614
Column 1 of triangle A132610 divided by row index less one.
4
1, 2, 13, 162, 3093, 80540, 2669415, 107660354, 5120654779, 280715282502, 17430145081600, 1209171149737470, 92693370560208210, 7781500380680157240, 710001855526865191083, 69962579484461463387330
OFFSET
1,2
COMMENTS
Triangle T=A132610 is generated by even matrix powers of itself such that row n+1 of T = row n of T^(2n) with appended '1' for n>=0 with T(0,0)=1.
FORMULA
a(n) = A132610(n+1,1)/n = A132612(n)/n for n>=1.
PROG
(PARI) {a(n)=local(A=vector(n+2), p); A[1]=1; if(n<1, 0, for(j=1, n-1, p=n^2-(n-j)^2; A=Vec((Polrev(A)+x*O(x^p))/(1-x))); A=Vec((Polrev(A)+x*O(x^p))/(1-x)); A[p+1]/n)}
CROSSREFS
Cf. A132610 (triangle); columns: A132611, A132612, A132613.
Sequence in context: A291140 A192563 A014507 * A187927 A252766 A098638
KEYWORD
nonn
AUTHOR
Paul D. Hanna, Aug 23 2007
STATUS
approved