Primes obtained from other primes by prefixing a 4.

Terms

a(0) =43a(1) =47a(2) =419a(3) =431a(4) =443a(5) =461a(6) =467a(7) =479a(8) =4127a(9) =4139a(10) =4157a(11) =4211a(12) =4229a(13) =4241a(14) =4271a(15) =4283a(16) =4337a(17) =4349a(18) =4373a(19) =4397a(20) =4409a(21) =4421a(22) =4457a(23) =4463a(24) =4523a(25) =4547a(26) =4643a(27) =4673a(28) =4691a(29) =4733