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%I #13 Jan 17 2019 13:44:08
%S 3,13,113,1113,111113,1111111113,111111111113,
%T 1111111111111111111111113,
%U 1111111111111111111111111111111111111111111111111111111111111111111111111111111111113
%N Primes of form R_n + 2 {= (10^n + 17)/9}, R_n being the n-th repunit, i.e., primes consisting of a string of 1's followed by a terminal 3.
%C For the associated positive values n see A097683.
%H Makoto Kamada, <a href="https://stdkmd.net/nrr/1/11113.htm#prime">Prime numbers of the form 11...113</a>.
%H <a href="/index/Pri#Pri_rep">Index entries for primes involving repunits</a>
%Y Cf. A098406.
%K nonn
%O 1,1
%A _Lekraj Beedassy_, Apr 08 2005