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 A128031 Numbers n such that (17^n - 3^n)/14 is prime. 28

%I

%S 3,11,17,491,23029

%N Numbers n such that (17^n - 3^n)/14 is prime.

%C All terms are primes.

%C No other terms <100,000.

%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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Last modified October 17 04:02 EDT 2019. Contains 328106 sequences. (Running on oeis4.)