A117259 Column 0 of triangle A117258.

1, 1, -2, 32, -2560, 917504, -1409286144, 9070970929152, -241505530017742848, 26378844025404658810880, -11755594669932654094842855424, 21291459481433341027538627037495296, -156279993920424129009046403691280672489472

Offset

0,3

Links

Table of n, a(n) for n=0..12.

Formula

a(n) = [prod_{j=0..n-1} (1-2*j)]/n! * 4^(n*(n-1)/2).

Prog

(PARI) {a(n)=local(m=1, p=2, q=4, r=1); prod(j=0, n-1, m*r-p*j)/n!*q^(n*(n-1)/2)}

Crossrefs

Sequence in context: A088386 A329928 A093584 * A234365 A068183 A166077

Adjacent sequences: A117256 A117257 A117258 * A117260 A117261 A117262

Keyword

sign

Author

Paul D. Hanna, Mar 14 2006

Status

approved