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 A114890 #2 Mar 30 2012 17:37:53 %S A114890 2,1,3,2,1,1,1,1,6,2,1,3,2,1,1,1,1,1,1,1,1,1,1,1,1,1,15,2,1,3,2,1,1,1, %T A114890 1,6,2,1,3,2,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1, %U A114890 1,1,1,1,1,1,1,1,1,1,1,1,42,2,1,3,2,1,1,1,1,6,2,1,3,2,1,1,1,1,1,1,1,1,1,1,1 %N A114890 First differences of A114889. %F A114890 Conjecture. a(1)=2 and, for n>1, a(n)=1+3+9+...+3^(k-1) + 2, if n=3^k, a(n)=a(n-3^k), if 3^k < n < 2*3^k - 1, else a(n)=1. (This has been verified for n<=3000.) %Y A114890 Cf. A114889. %K A114890 nonn %O A114890 1,1 %A A114890 _John W. Layman_, Jan 04 2006