Numbers k such that k concatenated with k+3 is a prime.

Terms

a(0) =4a(1) =8a(2) =10a(3) =16a(4) =44a(5) =46a(6) =56a(7) =58a(8) =68a(9) =74a(10) =86a(11) =94a(12) =98a(13) =100a(14) =104a(15) =106a(16) =136a(17) =140a(18) =148a(19) =154a(20) =158a(21) =160a(22) =166a(23) =176a(24) =184a(25) =194a(26) =206a(27) =230a(28) =244a(29) =250