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

Offset: 0

Author

Paul D. Hanna, Jun 04 2005

Keywords

• sign

Crossrefs

Cf. A107862, A107865.

Programs

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]}