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 A033495 #6 May 19 2013 12:18:39 %S A033495 1,2,3,6,7,9,15,27,54,55,63,126,171,199,231,327,447,639,703,937,1249, %T A033495 1407,1819,1915,2553,3831,4095,4255,5673,8511,9663,17179,20895,26623, %U A033495 35497,47329,52527,53247,56095,60975,77671,103561,113383,134379,159487 %N A033495 Initial number for record sum of numbers in trajectory of 3x+1 problem. %H A033495 <a href="/index/3#3x1">Index entries for sequences related to 3x+1 (or Collatz) problem</a> %K A033495 nonn %O A033495 0,2 %A A033495 _Jeff Burch_ %E A033495 More terms from Larry Reeves (larryr(AT)acm.org), Apr 27 2001