Primes having only {5, 6, 7, 9} as digits.

Terms

a(0) =5a(1) =7a(2) =59a(3) =67a(4) =79a(5) =97a(6) =557a(7) =569a(8) =577a(9) =599a(10) =659a(11) =677a(12) =757a(13) =769a(14) =797a(15) =967a(16) =977a(17) =997a(18) =5557a(19) =5569a(20) =5657a(21) =5659a(22) =5669a(23) =5779a(24) =6569a(25) =6577a(26) =6599a(27) =6659a(28) =6679a(29) =6779