OFFSET
-1,7
COMMENTS
Also McKay-Thompson series of class 69B for Monster. - Michel Marcus, Feb 24 2014
LINKS
Vaclav Kotesovec, Table of n, a(n) for n = -1..10000 (terms -1..2500 from G. C. Greubel)
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 -1 + A*B/q, where A = G(q^69)*G(q) + q^14*H(q^69)*H(q), B = G(q^23)*H(q^3) - q^4*H(q^23)*G(q^3), G() is g.f. of A003114 and H() is g.f. of A003106. - G. C. Greubel, Jun 30 2018
a(n) ~ exp(4*Pi*sqrt(n/69)) / (sqrt(2) * 69^(1/4) * n^(3/4)). - Vaclav Kotesovec, Jul 02 2018
EXAMPLE
T69A = 1/q + q + q^2 + q^3 + q^4 + 3*q^5 + 2*q^6 + 2*q^7 + 4*q^8 + 4*q^9 + ...
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]; A:= G[x^69]*G[x] + x^14*H[x^69]*H[x]; B:= G[x^23]*H[x^3] - x^4*H[x^23]*G[x^3]; a:= CoefficientList[Series[-1*x + A*B, {x, 0, 60}], x]; Table[a[[n]], {n, 1, 50}] (* G. C. Greubel, Jun 30 2018 *)
CROSSREFS
KEYWORD
nonn
AUTHOR
N. J. A. Sloane, Nov 27 2000
EXTENSIONS
More terms from Michel Marcus, Feb 24 2014
STATUS
approved