A104561 Column 0 of triangle A104560.

1, -1, 1, -2, 6, -30, 204, -1944, 23340, -360060, 6692280, -151908120, 4032593040, -126425330640, 4537069829880, -187762669281600, 8751745668796200, -462088269954518760, 27132285729049971120, -1779812144439507990000, 128512316060872730854560

Offset

0,4

Comments

A104560 equals the matrix inverse of A104559, where A104559(n,k) = C(n-[k/2],[(k+1)/2])*C(n-[(k+1)/2],[k/2]).

Links

Table of n, a(n) for n=0..20.

Prog

(PARI) {a(n)=local(M); M=matrix(n+1, n+1, m, j, if(m>=j, binomial(m-1-(j-1)\2, j\2)*binomial(m-1-j\2, (j-1)\2))); return((M^-1)[n+1, 1])}

Crossrefs

Cf. A104559, A104560.

Sequence in context: A176719 A203000 A334317 * A211211 A127482 A118747

Adjacent sequences: A104558 A104559 A104560 * A104562 A104563 A104564

Keyword

sign

Author

Paul D. Hanna, Mar 16 2005

Status

approved