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 A145171 #2 Mar 31 2012 10:28:54 %S A145171 1,1,1,1,2,0,1,0,0,1,1,1,1,1,1,1,2,0,0,0,0,1,0,0,2,0,0,0,1,1,1,2,2,2, %T A145171 0,0,1,2,0,1,2,0,1,2,0,1,0,0,0,0,0,0,0,0,1,1,1,1,0,0,0,0,0,0,1,1 %N A145171 Triangle read by rows: left half of trinomial triangle (A027907) modulo 3. %Y A145171 Cf. A027907, A111808 %K A145171 nonn,tabl %O A145171 1,5 %A A145171 _Reikku Kulon_, Oct 03 2008