Numbers n such that 6*10^n + 5*R_n + 4 is prime, where R_n = 11...1 is the repunit (A002275) of length n.

A103041

Numbers n such that 6*10^n + 5*R_n + 4 is prime, where R_n = 11...1 is the repunit (A002275) of length n.

Terms

    a(0) =2a(1) =5a(2) =8a(3) =17a(4) =20a(5) =65a(6) =83a(7) =90a(8) =108a(9) =252a(10) =335a(11) =1488a(12) =6356a(13) =65712a(14) =96798

External references