Numbers n such that 8*10^n + 3*R_n + 6 is prime, where R_n = 11...1 is the repunit (A002275) of length n.

A103078

Numbers n such that 8*10^n + 3*R_n + 6 is prime, where R_n = 11...1 is the repunit (A002275) of length n.

Terms

    a(0) =1a(1) =2a(2) =4a(3) =9a(4) =10a(5) =15a(6) =44a(7) =55a(8) =56a(9) =124a(10) =140a(11) =279a(12) =674a(13) =848a(14) =1420a(15) =1462a(16) =3314a(17) =3442a(18) =4141a(19) =35625

External references