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 A365666 #16 Jul 30 2025 05:02:22
%S A365666 1,2,4,8,14,24,40,64,100,144,212,304,424,588,800,1072,1422,1864,2408,
%T A365666 3080,3950,4972,6224,7760,9564,11742,14344,17384,20968,25204,30112,
%U A365666 35840,42548,50078,58888,69048,80474,93628,108608,125408,144536,166224,190348
%N A365666 Expansion of Sum_{0<i<j<k<l} q^(2*(i+j+k+l)-4)/( (1-q^(2*i-1))*(1-q^(2*j-1))*(1-q^(2*k-1))*(1-q^(2*l-1)) )^2.
%H A365666 G. E. Andrews and S. C. F. Rose, <a href="http://arxiv.org/abs/1010.5769">MacMahon's sum-of-divisors functions, Chebyshev polynomials, and Quasi-modular forms</a>, arXiv:1010.5769 [math.NT], 2010.
%F A365666 G.f.: (1/4) * ( Sum_{k>=4} (-1)^k * k * binomial(k+3,7) * q^(k^2) ) / ( 1 + 2 * Sum_{k>=1} (-q)^(k^2) ).
%t A365666 nmax = 60; Drop[CoefficientList[Series[1/4 * Sum[(-1)^k*k*Binomial[k + 3, 7]*x^(k^2), {k, 4, nmax}]/(1 + 2*Sum[(-x)^(k^2), {k, 1, nmax}]), {x, 0, nmax}], x], 16] (* _Vaclav Kotesovec_, Jul 30 2025 *)
%Y A365666 A diagonal of A060047.
%Y A365666 Cf. A002131, A002132, A060046, A365667.
%Y A365666 Cf. A015128.
%K A365666 nonn
%O A365666 16,2
%A A365666 _Seiichi Manyama_, Sep 15 2023