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 A127733 #3 Mar 30 2012 17:25:18 %S A127733 1,0,4,0,0,9,0,0,0,16,0,0,0,0,25,0,0,0,0,0,36,0,0,0,0,0,0,49 %N A127733 Square of A127648 = Triangle read by rows, n^2 preceded by (n-1) zeros. %e A127733 First few rows of the triangle are: %e A127733 1; %e A127733 0, 4; %e A127733 0, 0, 9; %e A127733 0, 0, 0, 16; %e A127733 0, 0, 0, 0, 25; %e A127733 ... %Y A127733 Cf. A127648. %K A127733 nonn,tabl %O A127733 1,3 %A A127733 _Gary W. Adamson_, Jan 26 2007