Numbers k such that k concatenated with k+9 is a prime.

Terms

a(0) =2a(1) =10a(2) =14a(3) =20a(4) =28a(5) =38a(6) =40a(7) =50a(8) =52a(9) =58a(10) =62a(11) =64a(12) =70a(13) =80a(14) =82a(15) =100a(16) =104a(17) =110a(18) =112a(19) =118a(20) =122a(21) =124a(22) =142a(23) =148a(24) =160a(25) =164a(26) =170a(27) =172a(28) =178a(29) =188