Numbers n such that 3*10^n - 1 is prime.

Terms

a(0) =0a(1) =1a(2) =3a(3) =6a(4) =7a(5) =19a(6) =27a(7) =43a(8) =55a(9) =207a(10) =1311a(11) =3204a(12) =7050a(13) =9439a(14) =26044a(15) =33058a(16) =34507a(17) =49314a(18) =119292