Numbers k such that 4*10^k - 99 is prime.

Terms

a(0) =4a(1) =6a(2) =7a(3) =9a(4) =43a(5) =53a(6) =67a(7) =69a(8) =123a(9) =178a(10) =201a(11) =448a(12) =649a(13) =658a(14) =1068a(15) =2003a(16) =2584a(17) =4445a(18) =4816a(19) =6322a(20) =8477a(21) =8868a(22) =14500a(23) =24934a(24) =33412a(25) =42504a(26) =87287a(27) =87337