%I A099414
%S A099414 0,3,5,6,48,108,245,1044
%N A099414 Numbers n such that 4*R_n + 5 is prime, where R_n = 11...1 is the repunit 
               (A002275) of length n.
%C A099414 Also numbers n such that (4*10^n+41)/9 is prime.
%H A099414 <a href="Sindx_Pri.html#Pri_rep">Index entries for primes involving repunits</
               a>
%t A099414 Do[ If[ PrimeQ[ 4(10^n - 1)/9 + 5], Print[n]], {n, 5000}]
%Y A099414 Sequence in context: A103022 A086189 A137082 this_sequence A099744 A024601 
               A085090
%Y A099414 Adjacent sequences: A099411 A099412 A099413 this_sequence A099415 A099416 
               A099417
%K A099414 nonn,more
%O A099414 1,2
%A A099414 Robert G. Wilson v (rgwv(AT)rgwv.com), Oct 14 2004