Numbers k such that (10^k + 47)/3 is prime.

Terms

a(0) =1a(1) =3a(2) =5a(3) =6a(4) =9a(5) =13a(6) =120a(7) =220a(8) =568a(9) =640a(10) =666a(11) =1205a(12) =1600a(13) =2479a(14) =2482a(15) =2939a(16) =3077a(17) =8649a(18) =9520a(19) =12407a(20) =33421a(21) =36162a(22) =41190a(23) =65340