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 A292141 #9 Sep 17 2017 03:35:31 %S A292141 1,1,1,-3,-3,-7,-11,-15,-19,-27,-15,-23,-15,-7,17,37,77,113,181,249, %T A292141 349,381,529,609,737,817,945,957,1037,1001,981,785,605,133,-303,-1095, %U A292141 -1727,-3015,-4191,-5963,-7667,-10095,-12379,-15495,-18339,-22067,-25631 %N A292141 a(n) = -A292140(n)/2. %H A292141 Seiichi Manyama, <a href="/A292141/b292141.txt">Table of n, a(n) for n = 0..10000</a> %Y A292141 Cf. A292140, A292143. %K A292141 sign %O A292141 0,4 %A A292141 _Seiichi Manyama_, Sep 09 2017