A136469 Column 2 of triangle A136467 (scaled): a(n) = A136467(n+2,2)/4^n.

1, 4, 36, 972, 82692, 22668224, 20480767016, 62399482333360, 654732295896172624, 24092174555680443592896, 3156168229958886081384337440, 1490220874303979634022445823087616

Offset

0,2

Links

Table of n, a(n) for n=0..11.

Prog

(PARI) {a(n)=local(M=matrix(n+3, n+3, r, c, binomial(r*2^(c-2), c-1)), P); P=matrix(n+3, n+3, r, c, binomial((r+1)*2^(c-2), c-1)); (P~*M~^-1)[n+3, 3]/4^n}

Crossrefs

Cf. A136467; A136468.

Sequence in context: A134052 A127901 A061742 * A120605 A337851 A353410

Adjacent sequences: A136466 A136467 A136468 * A136470 A136471 A136472

Keyword

nonn

Author

Paul D. Hanna, Dec 31 2007

Status

approved