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 A112051 #2 Mar 31 2012 14:02:21 %S A112051 1,3,11,24,60,84,144,180,264,420,480,684,840,924,1104,1404,1740,1860, %T A112051 2244,2520,2664,3120,3444,3960,4704,5100,5304,5724,5940,6384,8064, %U A112051 8580,9384,9660,11100,11400,12324,13284,13944,14964,16020,16380,18240 %N A112051 a(1)=1, a(n) = first index i (> a(n-1)), where A112046(i) gets a value distinct from any values A112046(1)..A112046(a(n-1)). %Y A112051 Column 1 of A112060 (row 1 of A112061). Cf. A112052. %K A112051 nonn %O A112051 1,2 %A A112051 _Antti Karttunen_, Aug 27 2005