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 A261631 #4 Aug 28 2015 03:15:02
%S A261631 1,3,6,10,18,30,46,69,105,154,219,309,434,597,813,1100,1476,1959,2585,
%T A261631 3387,4410,5709,7353,9414,12001,15231,19242,24205,30348,37902,47165,
%U A261631 58500,72342,89169,109599,134337,164221,200226,243537,295496,357732,432117,520858
%N A261631 Expansion of Product_{k>=0} 1/(1-x^(3*k+1))^3.
%F A261631 a(n) ~ exp(Pi*sqrt(2*n/3)) * Gamma(1/3)^3 / (4 * Pi^2 * sqrt(6*n)).
%t A261631 nmax=50; CoefficientList[Series[Product[1/(1-x^(3*k+1))^3, {k, 0, nmax}], {x, 0, nmax}], x]
%Y A261631 Cf. A035382, A261616, A261632.
%K A261631 nonn
%O A261631 0,2
%A A261631 _Vaclav Kotesovec_, Aug 27 2015