Primes p whose period of the reciprocal 1/p is (p-1)/3.

Terms

a(0) =103a(1) =127a(2) =139a(3) =331a(4) =349a(5) =421a(6) =457a(7) =463a(8) =607a(9) =661a(10) =673a(11) =691a(12) =739a(13) =829a(14) =967a(15) =1657a(16) =1669a(17) =1699a(18) =1753a(19) =1993a(20) =2011a(21) =2131a(22) =2287a(23) =2647a(24) =2659a(25) =2749a(26) =2953a(27) =3217a(28) =3229a(29) =3583