Unique-period primes in base 5 in the order they are found.
3, 31, 13, 7, 19531, 313, 521, 12207031, 601, 305175781, 5167, 390001, 234750601, 177635683940025046467781066894531, 152587500001, 227376585863531112677002031251, 59509429687890001, 11735415506748076408140121, 9080418348371887359375390001
1
T. D. Noe, Plot of 57 terms
T. D. Noe, Table of 57 terms
Chris K. Caldwell, Unique prime
(Mma) nn = 100; t5 = Table[c = Cyclotomic[n, 5]; c/GCD[n, c], {n, 2, nn}]; p5 = Select[t5, PrimePowerQ]; Table[FactorInteger[i][[1, 1]], {i, p5}]
Cf. A040017 (base-10 unique-period primes), A161509 (base 2), A064081.
nonn,base
T. D. Noe, May 14 2014