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 A217414 #10 Sep 07 2014 08:22:44 %S A217414 71,79,44,70,28,53,67,80,29,21,1653 %N A217414 2-adic valuation of A217413. %C A217414 These are the exponents on 2 in numbers of the form (2^r)*(11^s) in the main sequence. %e A217414 A217413(1)=(2^71)*(11^5), so this sequence's first term is 71. %Y A217414 Cf. A217413, A217415. %K A217414 nonn,base,less %O A217414 1,1 %A A217414 _James G. Merickel_, Oct 02 2012