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 A308806 #6 Jun 25 2019 18:48:56
%S A308806 1,1,1,1,1,2,3,4,5,6,8,11,14,18,23,30,40,52,67,86,111,145,188,243,314,
%T A308806 406,527,683,883,1141,1475,1910,2474,3201,4140,5355,6929,8968,11603,
%U A308806 15009,19416,25121,32507,42060,54413,70393,91071,117831,152453,197238,255175,330137,427130,552620
%N A308806 Expansion of 1 / Sum_{k>=0} (-x)^(k*(3*k - 1)/2).
%F A308806 G.f.: 1 / Sum_{k>=0} (-x)^A000326(k).
%t A308806 nmax = 53; CoefficientList[Series[1/Sum[(-x)^(k (3 k - 1)/2), {k, 0, nmax}], {x, 0, nmax}], x]
%Y A308806 Cf. A000041, A000326, A006950, A181324, A208061, A317665.
%K A308806 nonn
%O A308806 0,6
%A A308806 _Ilya Gutkovskiy_, Jun 25 2019