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 A138891 #2 Mar 30 2012 17:33:54 %S A138891 0,3,5,6,7,8,10,11,12,13,14,15,16,17,18,19,20,22,23,24,25,26,27,28,29, %T A138891 30,31,32,33,34,35,36,37,38,39,40,41,42,43,44,45,46,47,48,49,50,52,53, %U A138891 54,55,56,57,58,59,60,61,62,63,64,65,66,67,68,69,70,71,72,73,74,75,76 %N A138891 Non-Motzkin numbers. %C A138891 Nonnegative integers that are not in A001006. %Y A138891 Cf. A001006, A001690, A062289, A092460, A138836, A138888, A138890. %K A138891 easy,nonn %O A138891 1,2 %A A138891 _Omar E. Pol_, Apr 05 2008