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 A050134 #4 Mar 30 2012 18:57:01 %S A050134 2,4,5,7,11,15,18,21,23,26,30,31,34,37,39,43,46,47,50,54,58,61,63,66, %T A050134 70,74,75,79,82,86,87,90,93,95,98,102,106,109,111,115,118,122,123,126, %U A050134 127,130,134,138,141,143,147,150,151,154,158 %N A050134 a(n)=least k satisfying a(k)=3*k in A050132. %K A050134 nonn %O A050134 1,1 %A A050134 _Clark Kimberling_