OFFSET
-1,3
COMMENTS
Also McKay-Thompson series of class 31B for Monster.
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, Commun. Algebra 22, No. 13, 5175-5193 (1994).
David A. Madore, Coefficients of Moonshine (McKay-Thompson) series, The Math Forum
FORMULA
Expansion of (G(q^31)*H(q) - q^6*H(q^31)*G(q))^3 in powers of q, where G() is g.f. of A003114 and H() is g.f. of A003106. - G. C. Greubel, Jun 29 2018
Expansion of (T93A)^3 in powers of q, where T93A = A112217. - G. C. Greubel, Jun 29 2018
a(n) ~ exp(4*Pi*sqrt(n/31)) / (sqrt(2) * 31^(1/4) * n^(3/4)). - Vaclav Kotesovec, Jun 29 2018
EXAMPLE
T31A = 1/q + 3*q + 3*q^2 + 6*q^3 + 9*q^4 + 13*q^5 + 18*q^6 + 27*q^7 + ...
MATHEMATICA
QP := QPochhammer; f[x_, y_] := QP[-x, x*y]*QP[-y, x*y]*QP[x*y, x*y]; G[x_] := f[-x^2, -x^3]/f[-x, -x^2]; H[x_] := f[-x, -x^4]/f[-x, -x^2]; B:= G[x^31]*H[x] - x^6*H[x^31]*G[x]; a:= CoefficientList[Series[B^3, {x, 0, 50}], x]; Table[a[[n]], {n, 1, 50}] (* G. C. Greubel, Jun 29 2018 *)
CROSSREFS
KEYWORD
nonn
AUTHOR
N. J. A. Sloane, Nov 27 2000
EXTENSIONS
More terms from Michel Marcus, Feb 20 2014
STATUS
approved