%I A007615 M2890
%S A007615 3,11,37,101,333667,9091,9901,909091,1111111111111111111,
%T A007615 11111111111111111111111,99990001,999999000001,909090909090909091,
%U A007615 900900900900990990990991,9999999900000001
%N A007615 Primes with unique period length (the periods are given in A007498).
%D A007615 N. J. A. Sloane and Simon Plouffe, The Encyclopedia of Integer Sequences, 
               Academic Press, 1995 (includes this sequence).
%D A007615 Samuel Yates, Period Lengths of Exactly One or Two Prime Numbers, J. 
               Rec. Math., 18 (1985), 22-24.
%H A007615 T. D. Noe, <a href="b007615.txt">Table of n, a(n) for n=1..25</a>
%H A007615 <a href="Sindx_1.html#1overn">Index entries for sequences related to 
               decimal expansion of 1/n</a>
%H A007615 C. K. Caldwell, The Prime Glossary, <a href="http://primes.utm.edu/glossary/
               page.php?sort=UniquePrime">unique prime</a>
%e A007615 3 is the only prime p such that decimal expansion of 1/p has (nontrivial) 
               period exactly 1.
%Y A007615 Cf. A007498, A040017, A002371, A048595, A006883, A007732, A051626.
%Y A007615 Sequence in context: A061075 A005422 A040017 this_sequence A065540 A084171 
               A118044
%Y A007615 Adjacent sequences: A007612 A007613 A007614 this_sequence A007616 A007617 
               A007618
%K A007615 nonn,nice,easy,base
%O A007615 1,1
%A A007615 N. J. A. Sloane (njas(AT)research.att.com), Robert G. Wilson v (rgwv(AT)rgwv.com), 
               Mira Bernstein (mira(AT)math.berkeley.edu)