OFFSET
0,2
LINKS
G. C. Greubel, Table of n, a(n) for n = 0..5000
D. Ford, J. McKay and S. P. Norton, More on replicable functions, Commun. Algebra 22, No. 13, 5175-5193 (1994).
FORMULA
Expansion of A - 2*q/A, where A = q^(1/2)*eta(q^4)/eta(q^16), in powers of q. - G. C. Greubel, Jun 16 2018
EXAMPLE
T32d = 1/q - 2*q - q^7 - 2*q^9 - q^15 - 4*q^17 - 6*q^25 + q^31 + ...
MATHEMATICA
QP = QPochhammer; G[q_]:= QP[q^2, q^5]*QP[q^3, q^5]*QP[q^5, q^5]/QP[q, q]; H[q_]:= QP[q, q^5]*QP[q^4, q^5]*QP[q^5, q^5]/QP[q, q]; a[n_]:= SeriesCoefficient[(G[q]*G[q^19] + q^4*H[q]*H[q^19])^3/q - 3, {q, 0, n}]; Table[A058549[n], {n, -1, 50}] (* G. C. Greubel, Feb 18 2018 *)
eta[q_]:= q^(1/24)*QPochhammer[q]; A := q^(1/2)*eta[q^4]/eta[q^16]; a:=
CoefficientList[Series[(A - 2*q/A), {q, 0, 100}], q]; Table[a[[n]], {n, 1, 50}] (* G. C. Greubel, Jun 16 2018 *)
PROG
(PARI) q='q+O('q^50); A = eta(q^4)/eta(q^16); Vec(A - 2*q/A) \\ G. C. Greubel, Jun 16 2018
CROSSREFS
KEYWORD
sign
AUTHOR
Michael Somos, Aug 28 2005
STATUS
approved