Primes having only {2, 3, 9} as digits.

Terms

a(0) =2a(1) =3a(2) =23a(3) =29a(4) =223a(5) =229a(6) =233a(7) =239a(8) =293a(9) =929a(10) =2239a(11) =2293a(12) =2333a(13) =2339a(14) =2393a(15) =2399a(16) =2939a(17) =2999a(18) =3229a(19) =3299a(20) =3323a(21) =3329a(22) =3923a(23) =3929a(24) =9239a(25) =9293a(26) =9323a(27) =9923a(28) =9929a(29) =22229