%I A060261
%S A060261 257,379,811,971,1097,1217,2411,2539,2617,3011,4051,5297,5657,6211,
%T A060261 6337,6659,6857,8647,8807,10457,10651,10687,10937,11731,11939,12451,
%U A060261 12577,13099,14011,14537,14731,14887,15137,15607,15737,16091,16411
%N A060261 Denoting 5 consecutive primes by p, q, r, s and t, these are the values 
               of q such that q, r and s have 10 as a primitive root, but p and 
               t do not.
%C A060261 A prime p has 10 as a primitive root iff the length of the period of 
               the decimal expansion of 1/p is p-1.
%t A060261 test[p_] := MultiplicativeOrder[10, p]===p-1; Prime/@Select[Range[2, 
               2500], test[Prime[ # ]]&&test[Prime[ #+1]]&&test[Prime[ #+2]]&&!test[Prime[ 
               #-1]]&&!test[Prime[ #+3]]&]
%Y A060261 The indices of these primes are in A060260. Cf. A001913, A002371, A060259, 
               A060262.
%Y A060261 Sequence in context: A060879 A062382 A105345 this_sequence A158231 A070815 
               A095321
%Y A060261 Adjacent sequences: A060258 A060259 A060260 this_sequence A060262 A060263 
               A060264
%K A060261 nonn
%O A060261 0,1
%A A060261 Jeff Burch (gburch(AT)erols.com), Mar 23 2001
%E A060261 Edited by Dean Hickerson (dean.hickerson(AT)yahoo.com), Jun 17 2002