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 A158379 #4 Mar 02 2023 13:49:59
%S A158379 2,1,2,2,4,1,6,1,2,4,4,2,2,6,4,3,16,1,18,2,6,3,8,1,20,1,2,6,28,4,30,7,
%T A158379 4,16,10,2,18,18,2,2,8,6,42,8,4,11,18,3,42,20,16,4,52,1,20,3,18,28,26,
%U A158379 2,10,30,6,15,10,3,22,12,8,8,28,1,12,18,20,18,28,1,78,1,2,8,38,6,14,42,28
%N A158379 Period-lengths of the base-3 MR-expansions of the reciprocals of the positive integers.
%C A158379 See A136042 for the definition of the MR-expansion.
%C A158379 It appears that if p is a prime with 3 as a primitive root (A001122), then the MR-expansion of 1/p is periodic with period p-1.
%C A158379 The period lengths of the base-2 MR-expansions of the reciprocals of the positive integers are given in A136043.
%e A158379 The base-3 MR-expansion of 1/5 is {2,1,0,1,2,1,0,1,...} because 1/5->3/5->9/5->4/5->12/5->7/5->2/5->6/5->1/5->..., indicating that MR(1/5,3) begins {2,1,0,1,...} and has period 4. Thus a(5)=4.
%Y A158379 Cf. A001122, A007733, A115591, A136042, A136043, A136044, A155072.
%K A158379 nonn
%O A158379 1,1
%A A158379 _John W. Layman_, Mar 17 2009