OFFSET
0,2
PROG
(PARI) a(n)=polcoeff(prod(j=n+4, 2*n+6, 1-q^j)/prod(j=1, n+3, 1-q^j), 3*n+9, q)
CROSSREFS
KEYWORD
nonn
AUTHOR
Paul D. Hanna, Mar 10 2007
STATUS
approved