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 A292475 #9 Sep 17 2017 22:13:31 %S A292475 0,0,0,0,0,1,1,2,0,1,2,2,0,15,23,39,0,105,183,322,0,1016,1848,3347,0, %T A292475 10968,19943,36549,0,123086,227037,420857,0,1449771,2700611,5036699,0, %U A292475 17641455,33106802,62213791,0,220663135,416387896,786930971,0,2821102744 %N A292475 Number of solutions to 1 +- 5 +- 12 +- ... +- n*(3*n-1)/2 = 0. %F A292475 a(n) = A292474(n)/2. %Y A292475 Cf. A000326, A058498, A083527, A292474. %K A292475 nonn %O A292475 1,8 %A A292475 _Seiichi Manyama_, Sep 17 2017