|
%I #9 Mar 04 2021 01:42:16
%S 2,3,5,7,11,13,17,19,23,29,61,71
%N Primes p such that p^8 - 1 has fewer than 384 divisors.
%C For all primes p > 71, p^8 - 1 has at least A309906(8)=384 divisors.
%e p =
%e n a(n) factorization of p^8 - 1 a(n)
%e -- ---- ------------------------------------- ----
%e 1 2 3 * 5 * 17 8
%e 2 3 2^5 * 5 * 41 24
%e 3 5 2^5 * 3 * 13 * 313 48
%e 4 7 2^6 * 3 * 5^2 * 1201 84
%e 5 11 2^5 * 3 * 5 * 61 * 7321 96
%e 6 13 2^5 * 3 * 5 * 7 * 17 * 14281 192
%e 7 17 2^7 * 3^2 * 5 * 29 * 41761 192
%e 8 19 2^5 * 3^2 * 5 * 17 * 181 * 3833 288
%e 9 23 2^6 * 3 * 5 * 11 * 53 * 139921 224
%e 10 29 2^5 * 3 * 5 * 7 * 421 * 353641 192
%e 11 61 2^5 * 3 * 5 * 31 * 1861 * 6922921 192
%e 12 71 2^6 * 3^2 * 5 * 7 * 2521 * 12705841 336
%Y Cf. A000005, A000040, A309906, A342062, A342064.
%K nonn,fini,full
%O 1,1
%A _Jon E. Schoenfield_, Feb 27 2021
| 