%I #9 Feb 17 2017 11:58:52
%S 2,6,22,94,622,910,1058,1306,4430,18914,23654,35630,52846,63498,85630
%N Numbers n such that 5^n+4^(n-1) is prime.
%C a(16) > 10^5. - _Robert Price_, Mar 08 2016
%e 22 is a member since 522+421 = 2388583837526729 which is a prime number.
%t Do[ If[ PrimeQ[5^n + 4^(n - 1)], Print[n]], {n, 5000}]
%o (PARI) is(n)=isprime(5^n+4^(n-1)) \\ _Charles R Greathouse IV_, Feb 17 2017
%Y Cf. A082103, A093717, A093765, A096185, A093794, A093795, A096186.
%K nonn
%O 1,1
%A Herman H. Rosenfeld (herm3(AT)pacbell.net), May 17 2004
%E More terms from _Robert G. Wilson v_, Jun 18 2004
%E a(10)-a(15) from _Robert Price_, Mar 08 2016
|