OFFSET
-1,2
LINKS
G. C. Greubel, Table of n, a(n) for n = -1..1000
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^2)*eta(q^10)/(eta(q^4)* eta(q^20)), in powers of q. - G. C. Greubel, Jun 19 2018
EXAMPLE
T40b = 1/q - 2*q - q^3 - 2*q^5 - 2*q^9 - q^11 - 4*q^13 + q^15 - 4*q^17 - ...
MATHEMATICA
eta[q_]:= q^(1/24)*QPochhammer[q]; A:= q^(1/2)*(eta[q^2]*eta[q^10])/( eta[q^4]*eta[q^20]); a:= CoefficientList[Series[A - 2*q/A, {q, 0, 60}], q]; Table[a[[n]], {n, 1, 50}] (* G. C. Greubel, Jun 19 2018 *)
PROG
(PARI) q='q+O('q^50); A = eta(q^2)*eta(q^10)/(eta(q^4)*eta(q^20)); Vec(A - 2*q/A) \\ G. C. Greubel, Jun 19 2018
CROSSREFS
KEYWORD
sign
AUTHOR
N. J. A. Sloane, Nov 27 2000
EXTENSIONS
Terms a(12) onward added by G. C. Greubel, Jun 19 2018
STATUS
approved