Numbers k such that 9*10^k + 23 is prime.

Terms

a(0) =1a(1) =4a(2) =10a(3) =16a(4) =22a(5) =28a(6) =49a(7) =66a(8) =67a(9) =73a(10) =89a(11) =136a(12) =198a(13) =718a(14) =2674a(15) =3497a(16) =7894a(17) =9018a(18) =12058a(19) =16368a(20) =91693