OFFSET
0,2
EXAMPLE
A(x) = 1 + 4*x + 20*x^2 + 84*x^3 + 380*x^4 + 1540*x^5 +... =
1/[(1-4*x)*(1-16*x^2)^(1/4)*(1-64*x^3)^(1/16)*(1-256*x^4)^(1/64)*...]
PROG
(PARI) a(n)=polcoeff(prod(k=1, n, 1/(1-4^k*x^k+x*O(x^n))^(4/4^k)), n)
CROSSREFS
KEYWORD
nonn
AUTHOR
Paul D. Hanna, Jul 14 2005
STATUS
approved