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 A123838 #6 Oct 09 2013 14:20:53 %S A123838 1,13,869,69479,6131125,571764366,55449596876 %N A123838 Number of ways, counted up to symmetry, to build a contiguous building with n LEGO blocks of size 4 X 4. %Y A123838 Cf. A112389, A123762 - A123827, A123829 - A123849. %K A123838 nonn,hard %O A123838 1,2 %A A123838 _Søren Eilers_, Oct 29 2006