OFFSET
0,15
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
Expansion of sqrt(T70A + 2) in powers of q, where T70A = A058744. - G. C. Greubel, Jul 03 2018
a(n) ~ exp(2*Pi*sqrt(n/35)) / (2 * 35^(1/4) * n^(3/4)). - Vaclav Kotesovec, Jul 03 2018
EXAMPLE
T140a = 1/q +q +q^7 +q^11 +q^15 +q^19 +q^21 +q^23 +q^25 +...
MATHEMATICA
eta[q_] := q^(1/24)*QPochhammer[q]; nmax = 130; b:= eta[q]*eta[q^10]* eta[q^14]*eta[q^35]/(eta[q^2]*eta[q^5]*eta[q^7]*eta[q^70]); T70A:= 1 + b + 1/b; a:= CoefficientList[Series[(q*T70A + 2*q + O[q]^nmax)^(1/2), {q, 0, 100}], q]; Table[a[[n]], {n, 1, 80}] (* G. C. Greubel, Jul 03 2018 *)
PROG
(PARI) q='q+O('q^80); b = eta(q)*eta(q^10)* eta(q^14)*eta(q^35)/(q* eta(q^2)*eta(q^5)*eta(q^7)*eta(q^70)); T70A = b + 1 + 1/b; Vec(sqrt(q*( T70A + 2))) \\ G. C. Greubel, Jul 03 2018
CROSSREFS
KEYWORD
nonn
AUTHOR
Michael Somos, Aug 28 2005
STATUS
approved