Composite numbers k such that for all primes p dividing k, p-1 divides k-1 and p+1 divides k+1.

Terms

a(0) =8a(1) =27a(2) =32a(3) =125a(4) =128a(5) =243a(6) =343a(7) =512a(8) =1331a(9) =2048a(10) =2187a(11) =2197a(12) =3125a(13) =4913a(14) =6859a(15) =8192a(16) =12167a(17) =16807a(18) =19683a(19) =24389a(20) =29791a(21) =32768a(22) =50653a(23) =68921a(24) =74431a(25) =78125a(26) =79507a(27) =103823a(28) =131072a(29) =148877