A107866 - OEIS

A107866

Column 0 of triangle A107865.

1, -1, -1, -7, -77, -1145, -21410, -481683, -12655196, -379998938, -12830421321, -480984691304, -19816691903510, -889846823832596, -43247136243424267, -2261480610502143020, -126596066994553497948, -7553154370244179931495, -478456478496821309024061

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OFFSET

0,4

LINKS

Table of n, a(n) for n=0..18.

PROG

(PARI) {a(n)=(matrix(n+1, n+1, r, c, if(r>=c, binomial((r-1)*(r-2)/2-(c-1)*(c-2)/2+r-c, r-c)))^-1)[n+1, 1]}

CROSSREFS

Cf. A107862, A107865.

Sequence in context: A234466 A306031 A249933 * A034176 A001765 A246460

Adjacent sequences: A107863 A107864 A107865 * A107867 A107868 A107869

KEYWORD

sign

AUTHOR

Paul D. Hanna, Jun 04 2005

STATUS

approved