login

Year-end appeal: Please make a donation to the OEIS Foundation to support ongoing development and maintenance of the OEIS. We are now in our 61st year, we have over 378,000 sequences, and we’ve reached 11,000 citations (which often say “discovered thanks to the OEIS”).

A112197
McKay-Thompson series of class 56b for the Monster group.
1
1, 1, 1, -1, 1, 0, 2, -1, 2, 1, 3, -1, 4, 1, 4, 0, 5, 1, 7, -2, 8, 1, 10, -1, 12, 2, 14, -2, 17, 3, 21, -3, 24, 3, 28, -4, 34, 4, 39, -4, 46, 5, 53, -4, 61, 4, 71, -6, 82, 6, 94, -7, 108, 7, 124, -8, 142, 11, 162, -11, 185, 10, 210, -12, 238, 14, 271, -15, 306, 15, 345, -14, 390, 17, 439, -20, 494
OFFSET
0,7
LINKS
D. Ford, J. McKay and S. P. Norton, More on replicable functions, Comm. Algebra 22, No. 13, 5175-5193 (1994).
FORMULA
Expansion of A + q/A, where A = q^(1/2)*eta(q^4)*eta(q^14)/(eta(q^2)* eta(q^28)), in powers of q. - G. C. Greubel, Jul 01 2018
EXAMPLE
T56b = 1/q + q + q^3 - q^5 + q^7 + 2*q^11 - q^13 + 2*q^15 + q^17 + ...
MATHEMATICA
eta[q_] := q^(1/24)*QPochhammer[q]; A:= q^(1/2)*(eta[q^4]*eta[q^14]/(eta[q^2]*eta[q^28])); a:= CoefficientList[Series[A + q/A, {q, 0, 60}], q]; Table[a[[n]], {n, 1, 50}] (* G. C. Greubel, Jul 01 2018 *)
PROG
(PARI) q='q+O('q^50); A = eta(q^4)*eta(q^14)/(eta(q^2)*eta(q^28)); Vec(A + q/A) \\ G. C. Greubel, Jul 01 2018
CROSSREFS
Sequence in context: A361734 A263111 A260438 * A112198 A326850 A303756
KEYWORD
sign
AUTHOR
Michael Somos, Aug 28 2005
STATUS
approved