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A128563
Column 2 of triangle A128562.
1
1, 4, 12, 29, 61, 120, 222, 392, 669, 1109, 1792, 2838, 4413, 6751, 10184, 15169, 22332, 32538, 46955, 67162, 95288, 134173, 187593, 260562, 359682, 493622, 673736, 914814, 1236057, 1662340, 2225738, 2967500, 3940540, 5212495, 6869598
OFFSET
0,2
FORMULA
a(n) is the coefficient of q^(2*n+6) in the q-binomial coefficient [2*n+5, n+2].
PROG
(PARI) a(n)=polcoeff(prod(j=n+3, 2*n+5, 1-q^j)/prod(j=1, n+3, 1-q^j), 2*n+6, q)
CROSSREFS
Sequence in context: A014342 A086274 A174121 * A227085 A192978 A260546
KEYWORD
nonn
AUTHOR
Paul D. Hanna, Mar 10 2007
STATUS
approved