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%I #20 Mar 11 2023 23:06:35
%S 3,11,17,491,23029
%N Numbers k such that (17^k - 3^k)/14 is prime.
%C All terms are primes.
%C No other terms < 100000.
%t k=14; Select[ Prime[ Range[1,200] ], PrimeQ[ ((k+3)^# - 3^#)/k ]& ]
%o (PARI) is(n)=isprime((17^n-3^n)/14) \\ _Charles R Greathouse IV_, Feb 17 2017
%Y Cf. A028491 = numbers n such that (3^n - 1)/2 is prime.
%Y Cf. A057468 = numbers n such that 3^n - 2^n is prime.
%Y Cf. A059801 = numbers n such that 4^n - 3^n is prime.
%Y Cf. A121877 = numbers n such that (5^n - 3^n)/2 is a prime.
%Y Cf. A128024, A128025, A128026, A128027, A128028, A128029, A128030, A128032.
%K hard,more,nonn
%O 1,1
%A _Alexander Adamchuk_, Feb 11 2007
%E a(5)=23029 from _Robert Price_, Nov 03 2011
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