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 A244972 #12 Nov 14 2014 13:19:17 %S A244972 3,9,21,27,45,81,153,243,441,495,729 %N A244972 Orders of primitive groups not synchronizing a rank 3 map. %C A244972 Also, orders of graphs with clique number and chromatic number 3 which have primitive automorphism groups. %e A244972 The graphs on 3^n vertices are the Hamming graphs over 3-letter alphabet; the graphs with 21, 45 and 153 vertices are the line graphs of the 6-cage, 8-cage, and Biggs-Smith graph respectively. %K A244972 nonn,hard,more %O A244972 1,1 %A A244972 _Peter J. Cameron_, Nov 12 2014