OFFSET
-1,24
LINKS
G. C. Greubel, Table of n, a(n) for n = -1..1500
D. Ford, J. McKay and S. P. Norton, More on replicable functions, Comm. Algebra 22, No. 13, 5175-5193 (1994).
FORMULA
Expansion of A+ q^2/A, where A = q*(eta(q^3)*eta(q^18)*eta(q^30)* eta(q^45)/(eta(q^6)*eta(q^9)*eta(q^15)*eta(q^90))), in powers of q. - G. C. Greubel, Jul 02 2018
EXAMPLE
T90a = 1/q +q -q^2 +q^4 +q^7 +q^10 +q^13 +q^16 +q^19 -q^20 +...
MATHEMATICA
eta[q_] := q^(1/24)*QPochhammer[q]; A:= q*(eta[q^3]*eta[q^18]*eta[q^30]* eta[q^45]/(eta[q^6]*eta[q^9]*eta[q^15]*eta[q^90])); T90a := A + q^2/A; a:= CoefficientList[Series[T90a, {q, 0, 60}], q]; Table[a[[n]], {n, 1, 50}] (* G. C. Greubel, Jul 02 2018 *)
PROG
(PARI) q='q+O('q^80); A = (eta(q^3)*eta(q^18)*eta(q^30)* eta(q^45)/ (eta(q^6)*eta(q^9)*eta(q^15)*eta(q^90))); Vec(A + q^2/A) \\ G. C. Greubel, Jul 02 2018
CROSSREFS
KEYWORD
sign
AUTHOR
Michael Somos, Aug 28 2005
STATUS
approved