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 A093892 #7 Dec 05 2013 19:56:48 %S A093892 1,3,2,51,4,6,8,10,242,12,363,16,18,20,92,50,28,24,32,2514,30,1002, %T A093892 1434,894,36,474,678,1338,354,402,48,64,174,138,66,105,114,255,102,60, %U A093892 627,88,80,470,72,130,104,100,84,170,190,90,152,112,96,136,406,595,385,108 %N A093892 Index of first occurrence of n in A093890, or 0 if no such number exists. %C A093892 Conjecture: there are infinitely many zeros in this sequence. %F A093892 A093890[a(n)]=n. - _R. J. Mathar_, Feb 05 2007 %Y A093892 Cf. A093890, A093891. %K A093892 nonn %O A093892 0,2 %A A093892 _Amarnath Murthy_, Apr 23 2004 %E A093892 Corrected by _R. J. Mathar_, Feb 05 2007 %E A093892 More terms from _David Wasserman_, Apr 23 2007 %E A093892 Obsolete comment removed by _R. J. Mathar_, Jul 22 2009