Primes having only {1, 2, 5} as digits.

Terms

a(0) =2a(1) =5a(2) =11a(3) =151a(4) =211a(5) =251a(6) =521a(7) =1151a(8) =1511a(9) =2111a(10) =2221a(11) =2251a(12) =2521a(13) =2551a(14) =5521a(15) =11251a(16) =11551a(17) =12211a(18) =12251a(19) =12511a(20) =15121a(21) =15511a(22) =15551a(23) =21121a(24) =21211a(25) =21221a(26) =21521a(27) =22111a(28) =22511a(29) =25111