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 A189634 #4 Mar 30 2012 18:57:24 %S A189634 3,6,7,12,15,16,19,24,27,30,33,34,39,42,43,46,51,54,55,60,63,66,69,70, %T A189634 75,78,79,84,87,88,93,96,97,100,105,108,111,114,115,120,123,124,127, %U A189634 132,135,136,141,144,147,150,151,156,159,160,163,168,171,174,177,178,183,186,187,192,195,196,201,204,205,208,213,216,219,222,223,228,231,232,235,240,243 %N A189634 Positions of 1 in A189632; complement of A189633. %C A189634 See A189632. %t A189634 (See A189632.) %Y A189634 Cf. A189632, A189633, A189635. %K A189634 nonn %O A189634 1,1 %A A189634 _Clark Kimberling_, Apr 24 2011