%I #10 Jun 16 2018 18:32:37
%S 1,-1,0,-1,-1,0,0,-1,0,1,0,0,-1,0,0,-1,-1,0,2,-1,0,-2,-2,0,0,-1,0,2,
%T -1,0,-2,-1,0,-1,-2,0,4,-3,0,-4,-3,0,0,-3,0,5,-2,0,-4,-2,0,-2,-3,0,8,
%U -5,0,-7,-6,0,-1,-5,0,9,-4,0,-8,-4,0,-3,-6,0,14,-9,0,-13,-10,0,-2,-9,0,16,-8,0,-14,-8,0,-5,-11,0,24,-14,0,-21,-16,0,-3
%N McKay-Thompson series of class 36i for the Monster group.
%H G. C. Greubel, <a href="/A112178/b112178.txt">Table of n, a(n) for n = 0..5000</a>
%H D. Ford, J. McKay and S. P. Norton, <a href="http://dx.doi.org/10.1080/00927879408825127">More on replicable functions</a>, Comm. Algebra 22, No. 13, 5175-5193 (1994).
%H <a href="/index/Mat#McKay_Thompson">Index entries for McKay-Thompson series for Monster simple group</a>
%F Expansion of A - q/A, where A = q^(1/2)*(eta(q^3)*eta(q^18)^2* eta(q^27)/(eta(q^6)*eta(q^9)^2*eta(q^54))), in powers of q. - _G. C. Greubel_, Jun 16 2018
%e T36i = 1/q -q -q^5 -q^7 -q^13 +q^17 -q^23 -q^29 -q^31 +2*q^35 +...
%t eta[q_]:= q^(1/24)*QPochhammer[q]; A:= q^(1/2)*(eta[q^3]*eta[q^18]^2* eta[q^27]/(eta[q^6]*eta[q^9]^2*eta[q^54])); a:=CoefficientList[Series[A - q/A, {q, 0, 60}], q]; Table[a[[n]], {n, 1, 50}] (* _G. C. Greubel_, Jun 16 2018 *)
%o (PARI) q='q+O('q^50); A = (eta(q^3)*eta(q^18)^2* eta(q^27)/(eta(q^6) *eta(q^9)^2*eta(q^54))); Vec(A - q/A) \\ _G. C. Greubel_, Jun 16 2018
%K sign
%O 0,19
%A _Michael Somos_, Aug 28 2005