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 A064639 #8 Mar 20 2014 03:28:25 %S A064639 0,1,7,23,127,143,415,659,719,5167,5183,5455,5699,5759,16687,16703, %T A064639 26815,36899,36959,28495,38579,40031,40319,368047,368063,368335, %U A064639 368579,368639,379567,379583,389695,399779,399839,391375,401459,402911,403199 %N A064639 Positions of non-crossing fixed-point-free involutions encoded by A014486 (after reflection) in A055089. Permutation of A064640. %p A064639 map(PermRevLexRank,map(NonCrossingTransposRev, A014486)); NonCrossingTransposRev := n -> convert(NonCrossingTransposAux(deepreverse(binexp2pars(n)),1),'permlist',binwidth(n)); %Y A064639 Maple procedure deepreverse given in A057502, for others, follow A064638. Same sequence sorted: A064640. %K A064639 nonn %O A064639 0,3 %A A064639 _Antti Karttunen_, Oct 15 2001