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 A217432 #12 Sep 07 2014 08:41:53 %S A217432 25,10,20,48,10 %N A217432 3-adic valuation of A217431. %C A217432 A217431 consists of numbers of the form (3^r)*(13^s). This sequence holds the r values. %Y A217432 Cf. A217431, A217433. %K A217432 nonn,base,more %O A217432 1,1 %A A217432 _James G. Merickel_, Oct 03 2012