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 A182005 #13 Feb 13 2013 23:58:28 %S A182005 5,7,8,17,21,23,26,31,39,40,41,45,49,51,52,53,58,62,64,67,69,78,81,82, %T A182005 84,87,91,93,108,113,115,116,119,121,122,128,131,135,136,139,142,151, %U A182005 152,155,163,170,173,174,178,181,191,193,195,198,201 %N A182005 Let s(n) = s_3(n) be digit sum of n in base 3. Consider iterations: a_1(n) = s(2^n), a_2(n) = s(2^n+a_1(n)),a_3(n)=s(2^n+a_2(n)),...The sequence lists those n for which these iterations are (eventually) periodic with period > 1. %C A182005 For every number n which is not in the sequences, there exists N=N(n) such that, for k>N, a_k(n)=constant(k). %F A182005 Enlarged on 1 numbers which are not in A169655. %Y A182005 Cf. A053735, A000079. %K A182005 nonn,base %O A182005 1,1 %A A182005 _Vladimir Shevelev_ and _Peter J. C. Moses_, Apr 06 2012