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 A018860 #8 Mar 30 2012 18:35:08 %S A018860 0,4,39,1,51,3,23,53,78,5,25,40,60,75,90,2,17,27,42,52,62,72,82,92,4, %T A018860 9,19,24,34,39,49,54,59,64,74,79,84,89,94,6,11,16,21,119,26,31,36,41, %U A018860 46,51,56,154,61,66,71,267,76,81,86,184,91,96,194,3,8,204,13,18,116,23,317,28 %N A018860 4^a(n) is smallest power of 4 beginning with n. %H A018860 D. Mondot, <a href="/A018860/b018860.txt">Table of n, a(n) for n=1..32699</a> %K A018860 nonn,base %O A018860 1,2 %A A018860 _David W. Wilson_