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

Terms

a(0) =7a(1) =67a(2) =677a(3) =787a(4) =877a(5) =887a(6) =7687a(7) =7867a(8) =7877a(9) =8677a(10) =8867a(11) =8887a(12) =66877a(13) =67777a(14) =67867a(15) =68687a(16) =68767a(17) =68777a(18) =76667a(19) =76777a(20) =77687a(21) =77867a(22) =78787a(23) =78877a(24) =78887a(25) =86677a(26) =86767a(27) =87767a(28) =87877a(29) =87887