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 A292128 #20 Apr 13 2018 21:52:43
%S A292128 1,-3,-3,6,6,15,-12,-3,-30,-48,6,-12,15,78,186,-21,168,42,42,-246,
%T A292128 -408,-156,-399,-552,-498,-246,213,1248,-318,1608,1392,2508,1482,2976,
%U A292128 -480,-1011,1500,-1704,-4296,-4206,-8499,-8652,-7626,-7050,-192,-13008,-480,-2118
%N A292128 Expansion of Product_{k>=1} (1 - 3*x^k).
%H A292128 Seiichi Manyama, <a href="/A292128/b292128.txt">Table of n, a(n) for n = 0..10000</a>
%F A292128 G.f.: Sum_{i>=0} (-3)^i*x^(i*(i+1)/2)/Product_{j=1..i} (1 - x^j). - _Ilya Gutkovskiy_, Apr 13 2018
%o A292128 (PARI) N=66; x='x+O('x^N); Vec(prod(n=1, N, 1-3*x^n))
%Y A292128 Column k=3 of A292131.
%Y A292128 Product_{k>=1} (1 - m*x^k): A010815 (m=1), A070877 (m=2), this sequence (m=3).
%Y A292128 Cf. A032308, A242587, A292130.
%K A292128 sign
%O A292128 0,2
%A A292128 _Seiichi Manyama_, Sep 09 2017