A128072 Numbers k such that (3^k + 14^k)/17 is prime.

3, 7, 71, 251, 1429, 2131, 2689, 36683, 60763

Offset

1,1

Comments

All terms are primes.

a(10) > 10^5. - Robert Price, Apr 20 2013

Links

Table of n, a(n) for n=1..9.

Mathematica

k=14; Do[ p=Prime[n]; f=(3^p+k^p)/(k+3); If[ PrimeQ[f], Print[p]], {n, 1, 100} ]

Prog

(PARI) is(n)=isprime((3^n+14^n)/17) \\ Charles R Greathouse IV, Feb 17 2017

Crossrefs

Cf. A007658 (numbers k such that (3^k + 1)/4 is prime).

Cf. A057469 (numbers k such that (3^k + 2^k)/5 is prime).

Cf. A122853 (numbers k such that (3^k + 5^k)/8 is prime).

Cf. A128066, A128067, A128068, A128069, A128070, A128071, A128073, A128074, A128075.

Cf. A059801 (numbers k such that 4^k - 3^k is prime).

Cf. A121877 (numbers k such that (5^k - 3^k)/2 is prime).

Cf. A128024, A128025, A128026, A128027, A128028, A128029, A128030, A128031, A128032.

Sequence in context: A127179 A359748 A113841 * A094008 A209477 A209336

Adjacent sequences: A128069 A128070 A128071 * A128073 A128074 A128075

Keyword

hard,more,nonn

Author

Alexander Adamchuk, Feb 14 2007

Extensions

3 more terms from Ryan Propper, Jan 28 2008

a(8)-a(9) from Robert Price, Apr 20 2013

Status

approved