Primes having only {2, 6, 7, 8} as digits.

Terms

a(0) =2a(1) =7a(2) =67a(3) =227a(4) =277a(5) =677a(6) =727a(7) =787a(8) =827a(9) =877a(10) =887a(11) =2267a(12) =2287a(13) =2677a(14) =2687a(15) =2767a(16) =2777a(17) =2887a(18) =6277a(19) =6287a(20) =6827a(21) =7687a(22) =7727a(23) =7867a(24) =7877a(25) =8287a(26) =8627a(27) =8677a(28) =8867a(29) =8887