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A136469
Column 2 of triangle A136467 (scaled): a(n) = A136467(n+2,2)/4^n.
2
1, 4, 36, 972, 82692, 22668224, 20480767016, 62399482333360, 654732295896172624, 24092174555680443592896, 3156168229958886081384337440, 1490220874303979634022445823087616
OFFSET
0,2
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
Sequence in context: A134052 A127901 A061742 * A120605 A337851 A353410
KEYWORD
nonn
AUTHOR
Paul D. Hanna, Dec 31 2007
STATUS
approved