A057200 Numbers k such that 2^k + 17 is prime.

1, 13, 21, 33, 81, 129, 285, 297, 769, 3381, 4441, 7065, 77121, 133437, 184189, 191745, 1279921

Offset

1,2

Comments

a(17) > 5*10^5. - Robert Price, Oct 05 2015

For numbers k in this sequence, 2^(k-1)*(2^k+17) has deficiency 18 (see A223608). - M. F. Hasler, Jul 18 2016

All terms are odd. - Elmo R. Oliveira, Nov 19 2023

Links

Table of n, a(n) for n=1..17.

Henri Lifchitz and Renaud Lifchitz (Editors), Search for 2^n+17, PRP Top Records.

Mathematica

Do[ If[ PrimeQ[ 2^n + 17 ], Print[ n ]], {n, 0, 11811} ]
Select[Range[10000], PrimeQ[2^# + 17] &] (* Vincenzo Librandi, Aug 28 2015 *)

Prog

(Magma) [n: n in [0..1000] | IsPrime(2^n+17)]; // Vincenzo Librandi, Aug 28 2015
(PARI) is(n)=isprime(2^n+17) \\ Charles R Greathouse IV, Feb 17 2017

Crossrefs

Cf. A223608.

Cf. A019434 (primes 2^k+1), A057732 (2^k+3), A059242 (2^k+5), A057195 (2^k+7), A057196(2^k+9), A102633 (2^k+11), A102634 (2^k+13), A057197 (2^k+15), this sequence (2^k+17), A057221 (2^k+19), A057201 (2^k+21), A057203 (2^k+23).

Sequence in context: A164498 A164485 A164447 * A164454 A164426 A164473

Adjacent sequences: A057197 A057198 A057199 * A057201 A057202 A057203

Keyword

nonn,more,changed

Author

Robert G. Wilson v, Sep 16 2000

Extensions

a(13)-a(16) from Robert Price, Aug 24 2015

Edited by M. F. Hasler, Jul 18 2016

a(17) found by Stefano Morozzi, added by Elmo R. Oliveira, Nov 19 2023

Status

approved