A129278 Column 2 of triangle A129276; a(n) is the coefficient of q^(2n+2) in the squared q-factorial of n+2.
1, 8, 106, 1558, 23589, 360499, 5530445, 85040656, 1310211074, 20223812711, 312728963211, 4844238210807, 75161494829564, 1167972975649534, 18175688264003359, 283219807758089612, 4418626917709277371
Offset: 0
Keywords
Links
- Eric Weisstein's World of Mathematics, q-Factorial.
Programs
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PARI
a(n)=polcoeff(prod(i=1,n+2,(1-x^i)/(1-x))^2,2*n+2)
Formula
a(n) = [q^(2n+2)] Product_{i=1..n+2} { (1-q^i)/(1-q) }^2.