Numbers k such that (3*k + 1)/2 is prime.

Terms

a(0) =1a(1) =3a(2) =7a(3) =11a(4) =15a(5) =19a(6) =27a(7) =31a(8) =35a(9) =39a(10) =47a(11) =55a(12) =59a(13) =67a(14) =71a(15) =75a(16) =87a(17) =91a(18) =99a(19) =111a(20) =115a(21) =119a(22) =127a(23) =131a(24) =151a(25) =155a(26) =159a(27) =167a(28) =171a(29) =175