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 A050307 #5 Dec 19 2015 13:18:25 %S A050307 1,-4,1,6,-4,1,6,2,-4,1,-19,12,2,-4,1,-5,-7,8,2,-4,1,11,-18,-1,8,2,-4, %T A050307 1,16,-7,-6,-5,8,2,-4,1,26,13,-24,0,-5,8,2,-4,1,-10,19,11,-12,-4,-5,8, %U A050307 2,-4,1,-28,23,18,-6,-6,-4,-5,8,2,-4,1,-38,14,4,12,6,-10,-4,-5,8,2,-4 %N A050307 Matrix 4th power of inverse partition triangle A038498. %e A050307 1; -4,1; 6,-4,1; 6,2,-4,1; ... %Y A050307 Cf. A050305-A050313. %K A050307 sign,tabl %O A050307 1,2 %A A050307 _Christian G. Bower_, Aug 15 1999