OFFSET
-1,2
LINKS
G. C. Greubel, Table of n, a(n) for n = -1..2500
D. Ford, J. McKay and S. P. Norton, More on replicable functions, Comm. Algebra 22, No. 13, 5175-5193 (1994).
FORMULA
Expansion of A + 2*q/A, where A = q^(1/2)*(eta(q^3)*eta(q^9)/(eta(q^6)* eta(q^18))), in powers of q. - G. C. Greubel, Jun 23 2018
EXAMPLE
T36c = 1/q + 2*q - q^5 + 2*q^7 + 2*q^13 - 2*q^17 + 6*q^19 + 2*q^23 + 6*q^25 + ...
MATHEMATICA
eta[q_] := q^(1/24)*QPochhammer[q]; A:= q^(1/2)*(eta[q^3]*eta[q^9]/(eta[q^6]*eta[q^18])); a:= CoefficientList[Series[A + 2*q/A, {q, 0, 60}], q]; Table[a[[n]], {n, 1, 50}] (* G. C. Greubel, Jun 23 2018 *)
PROG
(PARI) q='q+O('q^50); A = (eta(q^3)*eta(q^9)/(eta(q^6)* eta(q^18))); Vec(A + 2*q/A) \\ G. C. Greubel, Jun 23 2018
CROSSREFS
KEYWORD
sign
AUTHOR
N. J. A. Sloane, Nov 27 2000
EXTENSIONS
Terms a(12) onward added by G. C. Greubel, Jun 23 2018
STATUS
approved