Primes in ternary.

Terms

a(0) =2a(1) =10a(2) =12a(3) =21a(4) =102a(5) =111a(6) =122a(7) =201a(8) =212a(9) =1002a(10) =1011a(11) =1101a(12) =1112a(13) =1121a(14) =1202a(15) =1222a(16) =2012a(17) =2021a(18) =2111a(19) =2122a(20) =2201a(21) =2221a(22) =10002a(23) =10022a(24) =10121a(25) =10202a(26) =10211a(27) =10222a(28) =11001a(29) =11012