

A057196


Numbers n such that 2^n + 9 is prime.


19



1, 2, 3, 5, 6, 7, 9, 10, 18, 23, 30, 37, 47, 57, 66, 82, 95, 119, 175, 263, 295, 317, 319, 327, 670, 697, 886, 1342, 1717, 1855, 2394, 2710, 3229, 3253, 3749, 4375, 4494, 4557, 5278, 5567, 9327, 10129, 12727, 13615, 14893, 16473, 23639, 40053, 44399, 50335, 80949
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OFFSET

1,2


COMMENTS

Some of the larger terms are only probable primes.
For these numbers n, 2^(n1)*(2^n+9) has deficiency 10, cf. A101223.  M. F. Hasler, Jul 18 2016


LINKS

Robert Price, Table of n, a(n) for n = 1..56
Keith Conrad, Square patterns and infinitude of primes, University of Connecticut, 2019.
H. Lifchitz & R. Lifchitz (Editors), PRP Top Records, of the form 2^n+9.


MATHEMATICA

Do[ If[ PrimeQ[ 2^n +9 ], Print[n]], { n, 1, 15000 }]


PROG

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


CROSSREFS

Cf. A104070 (primes of the form 2^n+3^2). [Klaus Brockhaus, Mar 14 2009]
Cf. A059242, A057732, A019434, A057195, A057197. [M. F. Hasler, Jul 18 2016]
Sequence in context: A179460 A171886 A018559 * A080637 A124134 A007071
Adjacent sequences: A057193 A057194 A057195 * A057197 A057198 A057199


KEYWORD

nonn


AUTHOR

Robert G. Wilson v, Sep 15 2000


EXTENSIONS

More terms from Mike Oakes, Aug 17 2001
Edited by T. D. Noe, Oct 30 2008


STATUS

approved



