OFFSET
0,6
LINKS
G. C. Greubel, Table of n, a(n) for n = 0..1000
D. Ford, J. McKay and S. P. Norton, More on replicable functions, Comm. Algebra 22, No. 13, 5175-5193 (1994).
FORMULA
a(n) ~ exp(Pi*sqrt(n/5)) / (2^(3/2) * 5^(1/4) * n^(3/4)). - Vaclav Kotesovec, Apr 30 2017
Expansion of q^(1/4)*(eta(q^2)*eta(q^10))^2/( eta(q)*eta(q^4)*eta(q^5) *eta(q^20)) in powers of q. - G. C. Greubel, Jun 20 2018
EXAMPLE
T80a = 1/q +q^3 +q^11 +q^15 +2*q^19 +2*q^23 +q^27 +3*q^31 +...
MATHEMATICA
nmax = 70; CoefficientList[Series[Product[(1 + x^(2*k-1))/((1 + x^(10*k))*(1 - x^(10*k-5))), {k, 1, nmax}], {x, 0, nmax}], x] (* Vaclav Kotesovec, Apr 30 2017 *)
eta[q_]:= q^(1/24)*QPochhammer[q]; a:= CoefficientList[Series[q^(1/4)*(eta[q^2]*eta[q^10])^2/( eta[q]*eta[q^4]*eta[q^5]*eta[q^20]), {q, 0, 60}], q]; Table[a[[n]], {n, 1, 70}] (* G. C. Greubel, Jun 20 2018 *)
PROG
(PARI) q='q+O('q^70); Vec((eta(q^2)*eta(q^10))^2/( eta(q)*eta(q^4) *eta(q^5)*eta(q^20))) \\ G. C. Greubel, Jun 20 2018
CROSSREFS
KEYWORD
nonn
AUTHOR
Michael Somos, Aug 28 2005
STATUS
approved