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 A018858 #8 Mar 30 2012 18:35:08 %S A018858 0,3,1,14,10,8,6,4,2,21,19,17,38,15,13,34,11,32,9,30,7,28,49,5,26,47, %T A018858 3,24,45,66,22,43,108,20,85,41,106,18,83,39,104,60,16,81,37,102,14, %U A018858 123,79,35,100,56,12,77,33,142,98,54,10,75,31,140,96,52,8,117,73,29,138,94,50,6 %N A018858 3^a(n) is smallest power of 3 beginning with n. %H A018858 D. Mondot, <a href="/A018858/b018858.txt">Table of n, a(n) for n=1..32699</a> %K A018858 nonn,base %O A018858 1,2 %A A018858 _David W. Wilson_