This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.
%I A058206 #39 Aug 11 2025 01:53:50
%S A058206 1,7,15,71,106,273,486,961,1563,3040,4692,8199,12773,20919,31569,
%T A058206 50552,74368,114504,167366,250033,358845,527650,745688,1073784,
%U A058206 1504452,2129317,2947224,4122518,5644462,7792122,10585876,14446420,19450323,26307536,35131220,47077341,62449405,82987854,109317927,144252191
%N A058206 McKay-Thompson series of class 12C for the Monster group.
%H A058206 G. C. Greubel, <a href="/A058206/b058206.txt">Table of n, a(n) for n = 0..1000</a> (terms 0..128 from G. A. Edgar)
%H A058206 D. Ford, J. McKay and S. P. Norton, <a href="http://dx.doi.org/10.1080/00927879408825127">More on replicable functions</a>, Commun. Algebra 22, No. 13, 5175-5193 (1994).
%H A058206 Michael Somos, <a href="/A007191/a007191.pdf">Emails to N. J. A. Sloane, 1993</a>
%H A058206 <a href="/index/Mat#McKay_Thompson">Index entries for McKay-Thompson series for Monster simple group</a>
%F A058206 Expansion of q^(1/2)*(eta(q^2)*eta(q^3)/(eta(q)*eta(q^6)))^6 + (eta(q)*eta(q^6)/(eta(q^2)*eta(q^3)))^6 in powers of q. - _G. A. Edgar_, Mar 13 2017
%F A058206 a(n) ~ exp(2*Pi*sqrt(n/3)) / (2*3^(1/4)*n^(3/4)). - _Vaclav Kotesovec_, Mar 18 2017
%F A058206 G.f. is a period 1 Fourier series which satisfies f(-1 / (24 t)) = f(t) where q = exp(2 Pi i t). - _Michael Somos_, Jul 06 2018
%e A058206 T12C = 1/q + 7*q + 15*q^3 + 71*q^5 + 106*q^7 + 273*q^9 + 486*q^11 + ...
%t A058206 QP := QPochhammer; CoefficientList[Series[QP[x^2]^6*QP[x^3]^6 / (QP[x]^6*QP[x^6]^6) + x*QP[x]^6*QP[x^6]^6 / (QP[x^2]^6*QP[x^3]^6), {x, 0, 66}], x] (* _Indranil Ghosh_, Mar 14 2017 *)
%t A058206 eta[q_]:= q^(1/24)*QPochhammer[q]; A := q^(1/2)*(eta[q^2]* eta[q^3]/( eta[q]*eta[q^6]))^6; a := CoefficientList[Series[A + q/A, {q, 0, 60}], q]; Table[a[[n]], {n, 1, 50}] (* _G. C. Greubel_, Jun 25 2018 *)
%t A058206 a[ n_] := With[{A = (QPochhammer[ x^3, x^6] / QPochhammer[ x, x^2])^6 }, SeriesCoefficient[ A + x / A, {x, 0, n}]]; Table[ a[ n], {n, 0, 39}] (* _Michael Somos_, Jul 06 2018 *)
%o A058206 (PARI) q='q+O('q^66); Vec( eta(q^2)^6*eta(q^3)^6 / (eta(q)^6*eta(q^6)^6) + q* eta(q)^6*eta(q^6)^6 / (eta(q^2)^6*eta(q^3)^6) ) \\ _Joerg Arndt_, Mar 13 2017
%Y A058206 Cf. A000521, A007240, A014708, A007241, A007267, A045478, etc.
%K A058206 nonn
%O A058206 0,2
%A A058206 _N. J. A. Sloane_, Nov 27 2000
%E A058206 More terms from _G. A. Edgar_, Mar 13 2017