Primes formed by the concatenation n, n+2, n.

Terms

a(0) =131a(1) =353a(2) =797a(3) =171917a(4) =232523a(5) =272927a(6) =293129a(7) =313331a(8) =333533a(9) =373937a(10) =495149a(11) =515351a(12) =575957a(13) =596159a(14) =616361a(15) =636563a(16) =676967a(17) =737573a(18) =777977a(19) =798179a(20) =838583a(21) =878987a(22) =899189a(23) =103105103a(24) =109111109a(25) =111113111a(26) =129131129a(27) =133135133