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 A285050 #14 Apr 27 2017 10:11:16
%S A285050 1,-1,0,0,-4,4,0,-7,13,-6,-10,38,-32,-9,74,-103,27,137,-266,153,191,
%T A285050 -593,537,167,-1161,1437,-222,-2035,3397,-1578,-3110,7160,-5285,-3712,
%U A285050 13942,-13920,-2002,24848,-32241,6764,40661,-68059,32487,59109,-133506,95221,71243
%N A285050 Expansion of Product_{k>=0} (1-x^(3*k+1))^(3*k+1).
%H A285050 Seiichi Manyama, <a href="/A285050/b285050.txt">Table of n, a(n) for n = 0..10000</a>
%Y A285050 Product_{k>=0} (1-x^(m*k+1))^(m*k+1): A285069 (m=2), this sequence (m=3), A285070 (m=4), A285071 (m=5).
%Y A285050 Cf. A262947.
%K A285050 sign
%O A285050 0,5
%A A285050 _Seiichi Manyama_, Apr 15 2017