Primes having only {0, 2, 7} as digits.

Terms

a(0) =2a(1) =7a(2) =227a(3) =277a(4) =727a(5) =2027a(6) =2207a(7) =2707a(8) =2777a(9) =7027a(10) =7207a(11) =7727a(12) =20707a(13) =22027a(14) =22277a(15) =22727a(16) =22777a(17) =27077a(18) =27277a(19) =70207a(20) =72077a(21) =72227a(22) =72277a(23) =72707a(24) =72727a(25) =200227a(26) =202277a(27) =202777a(28) =207227a(29) =222007