OFFSET
-1,3
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^2/A, where A = q*(eta(q^3)*eta(q^21)/(eta(q^6) *eta(q^42))), in powers of q. - G. C. Greubel, Jun 26 2018
EXAMPLE
T42c = 1/q + 2*q - q^2 + 2*q^4 + 2*q^7 - q^8 + 4*q^10 + q^11 + 4*q^13 - q^14 + ...
MATHEMATICA
eta[q_] := q^(1/24)*QPochhammer[q]; A:= q*(eta[q^3]*eta[q^21]/(eta[q^6] *eta[q^42])); a:= CoefficientList[Series[A + 2*q^2/A, {q, 0, 60}], q]; Table[a[[n]], {n, 1, 50}] (* G. C. Greubel, Jun 26 2018 *)
PROG
(PARI) q='q+O('q^70); A = (eta(q^3)*eta(q^21)/(eta(q^6)*eta(q^42))); Vec(A + 2*q^2/A) \\ G. C. Greubel, Jun 26 2018
CROSSREFS
KEYWORD
sign
AUTHOR
N. J. A. Sloane, Nov 27 2000
EXTENSIONS
Terms a(24) onward added by G. C. Greubel, Jun 26 2018
STATUS
approved