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 A204981 #5 Mar 30 2012 18:58:08 %S A204981 2,4,4,8,16,8,8,16,64,32,1024,16,4096,16,16,32,256,128,262144,64,64, %T A204981 2048,2048,32,1048576,8192,262144,32,268435456,32,32,64,1024,512,4096, %U A204981 256,68719476736,524288,4096,128,1048576,128,16384,4096,4096 %N A204981 Least 2^(k-1) such that n divides 2^(k-1)-2^(j-1) for some j<k. %C A204981 For a guide to related sequences, see A204892. %t A204981 (See the program at A204979.) %Y A204981 Cf. A204932, A204979. %K A204981 nonn %O A204981 1,1 %A A204981 _Clark Kimberling_, Jan 21 2012