Numbers n such that 6*10^n + 8*R_n - 1 is prime, where R_n = 11...1 is the repunit (A002275) of length n.

A103046

Numbers n such that 6*10^n + 8*R_n - 1 is prime, where R_n = 11...1 is the repunit (A002275) of length n.

Terms

    a(0) =0a(1) =1a(2) =33a(3) =72a(4) =177a(5) =192a(6) =325a(7) =417a(8) =732a(9) =1362a(10) =13947a(11) =14887a(12) =32706a(13) =63954a(14) =64783a(15) =82377

External references