%I #3 Sep 08 2022 08:45:51
%S 3,5,7,197
%N Primes p such that 19^p-18 is also prime.
%e For p=3, 19^3-18=6841; p=5, 19^5-18=2476081; p=7, 19^7-18=893871721
%o (Magma) [ p: p in PrimesUpTo(2000)| IsPrime(19^p-18)]
%K nonn
%O 1,1
%A _Vincenzo Librandi_, Mar 14 2010