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A007262
McKay-Thompson series of class 6c for Monster.
(Formerly M4078)
6
1, -6, 9, 16, -66, 54, 98, -300, 243, 364, -1128, 828, 1221, -3498, 2511, 3528, -9876, 6804, 9358, -25428, 17217, 23068, -61644, 40824, 53916, -141318, 92340, 119912, -310554, 199980, 256792, -656436, 418311, 530960, -1344144, 847584, 1066157, -2673372, 1671741, 2084464, -5186118, 3216834, 3981926, -9832752, 6057504, 7445924, -18269124, 11181636, 13661725, -33315852, 20274948, 24630344, -59740716
OFFSET
0,2
REFERENCES
N. J. A. Sloane and Simon Plouffe, The Encyclopedia of Integer Sequences, Academic Press, 1995 (includes this sequence).
LINKS
J. H. Conway and S. P. Norton, Monstrous Moonshine, Bull. Lond. Math. Soc. 11 (1979) 308-339.
D. Ford, J. McKay and S. P. Norton, More on replicable functions, Commun. Algebra 22, No. 13, 5175-5193 (1994).
J. McKay and H. Strauss, The q-series of monstrous moonshine and the decomposition of the head characters, Comm. Algebra 18 (1990), no. 1, 253-278.
FORMULA
G.f.: (E(q^2)/E(q^6))^6 / q where E(q) = Product_{n>=1} (1 - q^n); note that every second term is zero and is omitted in this sequence, cf. the PARI/GP code. - Joerg Arndt, Apr 09 2016
EXAMPLE
T6c = 1/q - 6*q + 9*q^3 + 16*q^5 - 66*q^7 + 54*q^9 + 98*q^11 - 300*q^13 + ...
MATHEMATICA
eta[q_] := q^(1/24)*QP0chhammer[q]; a[n_]:= SeriesCoefficient[ q^(-1)*(eta[q^2]/ eta[q^6])^6, {q, 0, n}]; Table[a[n], {n, 0, 50}] (* G. C. Greubel, Jan 25 2018 *)
PROG
(PARI) N=66; q='q+O('q^N); Vec( (eta(q^1)/eta(q^3))^6/q ) \\ Joerg Arndt, Apr 09 2016
CROSSREFS
Cf. A132107.
Sequence in context: A031326 A290791 A132107 * A129317 A316067 A316068
KEYWORD
sign
EXTENSIONS
More terms from Joerg Arndt, Apr 09 2016
STATUS
approved