%I A102959
%S A102959 1,4,34,36,42,52,163,208,216,1417
%N A102959 Numbers n such that 2*10^n + 7*R_n + 2 is prime, where R_n = 11...1 is 
               the repunit (A002275) of length n.
%C A102959 Also numbers n such that (25*10^n+11)/9 is prime.
%H A102959 Makoto Kamada, <a href="http://homepage2.nifty.com/m_kamada/math/27779.htm">
               Factorizations of 277...779</a>.
%H A102959 <a href="Sindx_Pri.html#Pri_rep">Index entries for primes involving repunits</
               a>.
%t A102959 Do[ If[ PrimeQ[(25*10^n + 11)/9], Print[n]], {n, 0, 10000}]
%Y A102959 Sequence in context: A113086 A058153 A020197 this_sequence A057959 A053902 
               A054464
%Y A102959 Adjacent sequences: A102956 A102957 A102958 this_sequence A102960 A102961 
               A102962
%K A102959 more,nonn
%O A102959 1,2
%A A102959 Robert G. Wilson v (rgwv(AT)rgwv.com), Dec 17 2004