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 A146599 #4 Mar 31 2012 12:35:11 %S A146599 1,1,1,1,1,1,1,1,1,1,3,3,7,7,19,19,51,51,237,237,1335,1335,8829 %N A146599 Number of n X n binary arrays symmetric about the diagonal and under 90 degree rotation with all ones connected only in a 1000-1000-1111 pattern in any orientation. %e A146599 Maximal 11 X 11 example %e A146599 .0.0.1.1.1.0.1.1.1.0.0 %e A146599 .0.0.0.0.1.0.1.0.0.0.0 %e A146599 .1.0.0.0.1.0.1.0.0.0.1 %e A146599 .1.0.0.0.1.0.1.0.0.0.1 %e A146599 .1.1.1.1.0.0.0.1.1.1.1 %e A146599 .0.0.0.0.0.0.0.0.0.0.0 %e A146599 .1.1.1.1.0.0.0.1.1.1.1 %e A146599 .1.0.0.0.1.0.1.0.0.0.1 %e A146599 .1.0.0.0.1.0.1.0.0.0.1 %e A146599 .0.0.0.0.1.0.1.0.0.0.0 %e A146599 .0.0.1.1.1.0.1.1.1.0.0 %K A146599 nonn %O A146599 1,11 %A A146599 _R. H. Hardin_, Nov 04 2008