Numbers k such that 2*10^k + 3*R_k + 6 is prime, where R_k = 11...1 is the repunit (A002275) of length k.

A102951

Numbers k such that 2*10^k + 3*R_k + 6 is prime, where R_k = 11...1 is the repunit (A002275) of length k.

Terms

    a(0) =1a(1) =2a(2) =3a(3) =4a(4) =8a(5) =11a(6) =13a(7) =24a(8) =28a(9) =52a(10) =54a(11) =94a(12) =297a(13) =657a(14) =1006a(15) =5347a(16) =8189a(17) =9314a(18) =23055a(19) =53287a(20) =64807a(21) =218644

External references