The On-Line Encyclopedia of Integer Sequences (OEIS)

Revision History for A057197

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A057197

Numbers k such that 2^k + 15 is prime.
(history; published version)

#23 by Michael De Vlieger at Mon Dec 11 11:44:38 EST 2023

STATUS

reviewed

approved

#22 by Michel Marcus at Mon Dec 11 10:55:59 EST 2023

STATUS

proposed

reviewed

#21 by Elmo R. Oliveira at Mon Dec 11 10:49:03 EST 2023

STATUS

editing

proposed

#20 by Elmo R. Oliveira at Mon Dec 11 10:46:37 EST 2023

DATA

1, 2, 3, 4, 5, 6, 8, 10, 11, 12, 15, 16, 22, 23, 26, 30, 32, 40, 42, 46, 61, 72, 76, 155, 180, 198, 203, 310, 328, 342, 508, 510, 515, 546, 808, 1563, 2772, 3882, 3940, 4840, 7518, 11118, 11552, 11733, 12738, 12858, 17421, 44122, 64660, 163560, 172455, 180496, 325866, 481840, 1009168

COMMENTS

For these numbers n, k, 2^(nk-1)*(2^nk+15) has deficiency 16, cf. (see A125248). - M. F. Hasler, Jul 18 2016

LINKS

H. Henri Lifchitz & R. and Renaud Lifchitz (Editors), <a href="http://www.primenumbers.net/prptop/searchform.php?form=2%5En%2B15">Search for 2^n+15</a>, PRP Top Records, of the form 2^n+15</a>.

EXAMPLE

For k = 5, 2^5 + 15 = 47 is prime.

For k = 15, 2^15 + 15 = 32783 is prime.

CROSSREFS

Cf. A059242, A057732, A019434, A057195A094076, A125248.

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), this sequence (2^k+15), A057200 (2^k+17), A057221 (2^k+19), A057201 (2^k+21), A057203 (2^k+23).

EXTENSIONS

a(55) from Stefano Morozzi, added by Elmo R. Oliveira, Dec 11 2023

STATUS

approved

editing

#19 by Alois P. Heinz at Wed Nov 08 07:48:21 EST 2023

STATUS

editing

approved

#18 by Alois P. Heinz at Wed Nov 08 07:48:19 EST 2023

NAME

Numbers n k such that 2^n k + 15 is prime.

STATUS

approved

editing

#17 by Charles R Greathouse IV at Thu Sep 08 08:45:02 EDT 2022

PROG

(MAGMAMagma) [n: n in [0..1500] | IsPrime(2^n+15)]; // Vincenzo Librandi, Aug 28 2015

Discussion

Thu Sep 08

08:45

OEIS Server: https://oeis.org/edit/global/2944

#16 by M. F. Hasler at Mon Jul 18 03:39:18 EDT 2016

STATUS

editing

approved

#15 by M. F. Hasler at Mon Jul 18 03:37:25 EDT 2016

COMMENTS

For these numbers n, 2^(n-1)*(2^n+15) has deficiency 16, cf. A125248. - M. F. Hasler, Jul 18 2016

LINKS

H. Lifchitz & R. Lifchitz (Editors), <a href="http://www.primenumbers.net/prptop/searchform.php?form=2%5En%2B15">PRP Top Records, of the form 2^n+15</a>.

PROG

(PARI) for(n=1, 9e9, ispseudoprime(2^n+15)&&print1(n", ")) \\ M. F. Hasler, Jul 18 2016

CROSSREFS

Cf. A059242, A057732, A019434, A057195.

STATUS

approved

editing

#14 by Alois P. Heinz at Mon Sep 14 14:07:23 EDT 2015

STATUS

proposed

approved