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 A363149 #13 May 26 2023 08:50:29
%S A363149 1,-1,1,-1,1,-1,1,-2,3,-4,5,-6,7,-8,10,-13,17,-22,27,-33,40,-49,61,
%T A363149 -77,98,-123,153,-189,233,-288,358,-448,561,-701,872,-1082,1342,-1666,
%U A363149 2073,-2584,3223,-4016,4997,-6212,7720,-9598,11942,-14869,18517,-23053,28687
%N A363149 Expansion of 1 / Sum_{k>=0} x^(k*(5*k - 3)/2).
%t A363149 nmax = 50; CoefficientList[Series[1/Sum[x^(k (5 k - 3)/2), {k, 0, nmax}], {x, 0, nmax}], x]
%Y A363149 Cf. A000566, A106507, A308806, A317665, A322799, A361979, A363275.
%K A363149 sign
%O A363149 0,8
%A A363149 _Ilya Gutkovskiy_, May 25 2023