%I #9 Aug 04 2019 04:41:24

%S 54,3076,11796

%N Numbers k such that 7^k + k^7 is prime.

%C a(4) > 110000.

%Y Cf. A001596, A114974, A309421.

%K nonn,bref,more,hard

%O 1,1

%A _Hugo Pfoertner_, Jul 30 2019