Numbers k such that k concatenated with k+2 is a lucky number.

Terms

a(0) =1a(1) =7a(2) =19a(3) =25a(4) =31a(5) =49a(6) =61a(7) =65a(8) =71a(9) =77a(10) =101a(11) =103a(12) =107a(13) =121a(14) =125a(15) =133a(16) =139a(17) =149a(18) =157a(19) =169a(20) =173a(21) =193a(22) =205a(23) =221a(24) =233a(25) =245a(26) =295a(27) =349a(28) =359a(29) =371