Search: id:A103063 Results 1-1 of 1 results found. %I A103063 %S A103063 1,2,6,25,69,253,300,384,434,721,822,883,2192,2649,3441,3445,8028 %N A103063 Numbers n such that 7*10^n + 6*R_n - 5 is prime, where R_n = 11...1 is the repunit (A002275) of length n. %C A103063 Also numbers n such that (23*10^n-17)/3 is prime. %H A103063 Makoto Kamada, Factorizations of 766...661. %H A103063 Index entries for primes involving repunits. %t A103063 Do[ If[ PrimeQ[(23*10^n - 17)/3], Print[n]], {n, 0, 10000}] %Y A103063 Sequence in context: A123150 A086591 A073545 this_sequence A030228 A066317 A027104 %Y A103063 Adjacent sequences: A103060 A103061 A103062 this_sequence A103064 A103065 A103066 %K A103063 more,nonn %O A103063 1,2 %A A103063 Robert G. Wilson v (rgwv(AT)rgwv.com), Jan 19 2005 Search completed in 0.001 seconds