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%I #14 Aug 17 2021 02:15:02
%S 79,241,727,2399,14639,19681,28559,371291,707279,823541,1771559,
%T 2825759,3418799,5764799,7890479,12117359,24137567,28398239,28629149,
%U 47458319,104060399,1073283119,2565726407,3262808639,3373402559,5887339439,6103515623,7370050799,9354951839,10779215327,13841287199
%N Primes that are of the form p^k-2 for some k > 3 and prime p.
%H Robert Israel, <a href="/A347032/b347032.txt">Table of n, a(n) for n = 1..1000</a>
%e a(3) = 727 is a term because 727 = 3^6-2, 6 > 3 and 727 and 3 are prime.
%p N:= 10^12: # for terms <= N
%p R:= {}:
%p p:= 1:
%p do
%p p:= nextprime(p);
%p if p^4-2 > N then break fi;
%p for k from 4 to ilog[p](N) do
%p r:= p^k - 2;
%p if isprime(r) then R:= R union {r} fi;
%p od
%p od:
%p sort(convert(R,list));
%o (PARI) isok(p) = isprime(p) && (isprimepower(p+2) > 3); \\ _Michel Marcus_, Aug 16 2021
%K nonn
%O 1,1
%A _J. M. Bergot_ and _Robert Israel_, Aug 11 2021