Primes having only {4, 5, 7, 8} as digits.

Terms

a(0) =5a(1) =7a(2) =47a(3) =457a(4) =487a(5) =547a(6) =557a(7) =577a(8) =587a(9) =757a(10) =787a(11) =857a(12) =877a(13) =887a(14) =4447a(15) =4457a(16) =4547a(17) =4787a(18) =4877a(19) =5477a(20) =5557a(21) =5857a(22) =7457a(23) =7477a(24) =7487a(25) =7547a(26) =7577a(27) =7757a(28) =7877a(29) =8447