OFFSET
0,3
LINKS
G. C. Greubel, Table of n, a(n) for n = 0..2500
D. Ford, J. McKay and S. P. Norton, More on replicable functions, Comm. Algebra 22, No. 13, 5175-5193 (1994).
FORMULA
Expansion of (T9b - 3*q)^(1/3), where T9b = A112146, in powers of q. - G. C. Greubel, Jun 25 2018
EXAMPLE
T27e = 1/q - q^2 + 2*q^5 + 3*q^8 + q^14 + 3*q^17 - 2*q^20 + 3*q^23 + ...
MATHEMATICA
eta[q_] := q^(1/24)*QPochhammer[q]; nmax = 100; A:= q*(eta[q^3]/eta[q^9] )^4; T9b := A + 9*q^2/A; a:= CoefficientList[Series[(T9b - 3*q + O[q]^nmax)^(1/3), {q, 0, 60}], q]; Table[a[[n]], {n, 1, 50}] (* G. C. Greubel, Jun 25 2018 *)
PROG
(PARI) q='q+O('q^50); A = (eta(q^3)/eta(q^9))^4; T9b = A + 9*q^2/A; Vec((T9b - 3*q)^(1/3)) \\ G. C. Greubel, Jun 25 2018
CROSSREFS
KEYWORD
sign
AUTHOR
Michael Somos, Aug 28 2005
STATUS
approved