OFFSET
0,3
COMMENTS
LINKS
G. C. Greubel, Table of n, a(n) for n = 0..1000
Michael Somos, Introduction to Ramanujan theta functions
Eric Weisstein's World of Mathematics, Ramanujan Theta Functions
FORMULA
Expansion of q^(1/8)*((eta(q^3)/ eta(q^6))^8 + 16*(eta(q^6)/ eta(q^3))^8)^(1/8) in powers of q.
MATHEMATICA
eta[q_]:= q^(1/24)*QPochhammer[q]; a[n_] := SeriesCoefficient[q^(1/8)*((eta[q^3]/eta[q^6])^8 + 16*(eta[q^6]/eta[q^3])^8)^(1/8), {q, 0, n}]; Table[a[n], {n, 0, 50}] (* G. C. Greubel, Mar 07 2018 *)
PROG
(PARI) {a(n)=local(A); if(n<0, 0, A=x*O(x^n); A=(eta(x^3+A)/eta(x^6+A))^8; polcoeff( (A+16*x^2/A)^(1/8), n))}
CROSSREFS
KEYWORD
sign
AUTHOR
Michael Somos, Apr 25 2005
STATUS
approved