Numbers k such that k concatenated with k+1 is prime.

Terms

a(0) =2a(1) =6a(2) =8a(3) =12a(4) =36a(5) =42a(6) =50a(7) =56a(8) =62a(9) =68a(10) =78a(11) =80a(12) =90a(13) =92a(14) =96a(15) =102a(16) =108a(17) =120a(18) =126a(19) =138a(20) =150a(21) =156a(22) =180a(23) =186a(24) =188a(25) =192a(26) =200a(27) =216a(28) =242a(29) =246