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 A055173 #4 Mar 30 2012 18:57:03 %S A055173 1,3,4,6,2,8,11,5,13,16,10,7,18,12,9,22,14,25,28,21,15,19,30,24,35,27, %T A055173 20,38,29,17,42,34,23,31,45,36,50,41,39,52,44,26,56,49,37,47,59,33,64, %U A055173 54,55,32,66,57,48,40,60,71,61,62,46,77,63 %N A055173 n-th distinct number to appear in A055171; also the n-th to appear in A055187. %C A055173 Conjecture: this sequence is a permutation of the positive integers. %K A055173 nonn %O A055173 1,2 %A A055173 _Clark Kimberling_, Apr 27 2000