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 A217411 #9 Sep 07 2014 08:35:18 %S A217411 37,43,3,51,32,56,56,57,50,54,88,44,25,64,99,23,503 %N A217411 3-adic valuation of A217410. %C A217411 These are the exponents on 3 in numbers of the form (3^r)*(7^s) of the main sequence. %e A217411 A217410(1)=(3^37)*(7^10), so this sequence's first term is 37. %Y A217411 Cf. A217410, A217412. %K A217411 nonn,base,less %O A217411 1,1 %A A217411 _James G. Merickel_, Oct 02 2012