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 (T10b + 4)^(1/2), where T10b = A058103, in powers of q. - G. C. Greubel, Jun 21 2018
EXAMPLE
T20e = 1/q + 2*q - q^3 + 3*q^7 + 3*q^11 - 4*q^13 + 2*q^17 + 3*q^19 + ...
MATHEMATICA
eta[q_] := q^(1/24)*QPochhammer[q]; nmax = 100; A:= eta[q]/eta[q^25]; B:= (eta[q^2]*eta[q^25])/(eta[q]*eta[q^50]); c := ((eta[q]*eta[q^2])/( eta[q^5]*eta[q^10]))^2; d:= ((eta[q^5]*eta[q^10])/( eta[q^25]*eta[q^50]) )^2; T10b := (2 + c + 5*(c/(A)^2)*(1 - 1/B)^2 + 25/d); a:= CoefficientList[Series[(q*(T10b + 4) + O[q]^nmax)^(1/2), {q, 0, nmax}], q]; Table[a[[n]], {n, 1, nmax}] (* G. C. Greubel, Jun 21 2018, fixed by Vaclav Kotesovec, Jul 03 2018 *)
CROSSREFS
KEYWORD
sign
AUTHOR
N. J. A. Sloane, Nov 27 2000
EXTENSIONS
Terms a(12) onward added by G. C. Greubel, Jun 21 2018
STATUS
approved