Digit '9' concatenated with a(n) is a lucky number.

Terms

a(0) =3a(1) =9a(2) =25a(3) =27a(4) =31a(5) =33a(6) =37a(7) =57a(8) =61a(9) =75a(10) =79a(11) =81a(12) =91a(13) =93a(14) =97a(15) =115a(16) =117a(17) =121a(18) =123a(19) =135a(20) =139a(21) =145a(22) =151a(23) =177a(24) =181a(25) =211a(26) =213a(27) =223a(28) =231a(29) =235