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 A075174 #2 May 01 2014 02:44:55 %S A075174 1,2,3,6,0,4,0,12,5,10,15,30,0,20,0,60,0,0,0,0,0,8,0,24,0,0,0,0,0,40, %T A075174 0,120,0,0,9,18,0,0,0,36,0,0,45,90,0,0,0,180,0,0,0,0,0,0,0,72,0,0,0,0, %U A075174 0,0,0,360,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,16,0,48,0,0,0,0,0 %N A075174 Inverse function of N -> N injection A075173. %C A075174 a(n) = 0 for those n which do not occur as the values of A075173. All positive natural numbers occur here once. %Y A075174 a(A075173(n)) = n for all n >= 1. Differs from A075176 for first time at a(18) = 0, while A075176(18) = 9. %K A075174 nonn %O A075174 0,2 %A A075174 _Antti Karttunen_, Sep 13 2002