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 A169866 #2 Mar 30 2012 16:51:45 %S A169866 1,3,4,6,8,10,12,11,13,15,17,19,21,23,22,24,26,28,30,32,34,36,38,37, %T A169866 39,41,43,45,47,49,51,53,55,57,59,61,63,56,58,60,62,64,66,68,70,72,74, %U A169866 76,78,80,82,84,86 %N A169866 The sequence S of a pair of complementary sequences (S, T) which are similar to the pairs (A093848, A169863), (A169864, A169865), except that here the lengths of the equal-parity runs of one sequence are given by the other. %Y A169866 Cf. A169867, A001462, A093848, A169863, A169864, A169865. %K A169866 nonn,more %O A169866 1,2 %A A169866 _N. J. A. Sloane_, Jun 27 2010, following a posting from Eric Angelini to the Sequence Fans Mailing List, Jun 22, 2010