OFFSET
1,3
COMMENTS
The q-Pochhammer symbol (a;q)_inf = Product_{k>=0} (1 - a*q^k).
a(n) agrees with A118399(n) for n < 15.
LINKS
G. C. Greubel, Table of n, a(n) for n = 1..5000
Eric Weisstein's World of Mathematics, q-Pochhammer Symbol.
FORMULA
a(n) ~ sqrt(1 + sqrt(2)) * c^(1/4) * exp(2*sqrt(c*n)) / (8*sqrt(Pi)*n^(3/4)), where c = Pi^2/6 + log(2)^2/8 + polylog(2, -1/sqrt(2)) = 1.0944511783086747574574059... - Vaclav Kotesovec, Oct 11 2018
MATHEMATICA
((QPochhammer[Sqrt[2], x] + QPochhammer[-Sqrt[2], x] - 2)/4 + O[x]^53)[[3]]
CROSSREFS
KEYWORD
nonn
AUTHOR
Vladimir Reshetnikov, Nov 17 2016
STATUS
approved