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 A094173 #11 Apr 03 2014 00:11:45 %S A094173 1,2,1,3,2,4,5,3,6,7,4,3,5,8,9 %N A094173 a(n) = m if m has already occurred at least once and n=k+i*(m+1) where k is the index of the first occurrence of n and i=1,...,max(n-1,1), otherwise a(n) = least positive integer that has not yet occurred. %C A094173 Is the sequence possible for all n? %C A094173 a(16) does not exist: it would have to be 4 (since a(6) = a(11) = 4 and so a(6 + 2*(4 + 1)) = a(16) = 4) and also 6 (since a(9) = 6 and so a(9 + 1*(6 + 1)) = a(16) = 6) simultaneously. - Herman Jamke (hermanjamke(AT)fastmail.fm), May 01 2008 %Y A094173 Cf. A095162, A095163, A095164. %K A094173 nonn,fini,full %O A094173 1,2 %A A094173 _Amarnath Murthy_, Jun 01 2004 %E A094173 Edited by Herman Jamke (hermanjamke(AT)fastmail.fm), May 01 2008