

A102633


Numbers n such that 2^n+11 is prime.


11



1, 3, 5, 7, 9, 15, 23, 29, 31, 55, 71, 77, 297, 573, 1301, 1555, 1661, 4937, 5579, 6191, 6847, 6959, 19985, 26285, 47093, 74167, 149039, 175137, 210545, 240295, 306153, 326585, 345547
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OFFSET

1,2


COMMENTS

a(34) > 5*10^5.  Robert Price, Aug 26 2015
For numbers n in this sequence, 2^(n1)*(2^n+11) has deficiency 12, cf. A141549. All terms are odd since 4^n+11 == 1+2 == 0 (mod 3).  M. F. Hasler, Jul 18 2016


LINKS

Table of n, a(n) for n=1..33.
H. Lifchitz & R. Lifchitz (Editors), PRP Top Records, of the form 2^n+11.
Lei Zhou, Between 2^n and primes. [broken link]


EXAMPLE

2^1+11 = 13 is prime
2^3+11 = 19 is prime
2^2+11 = 15 is not prime


MATHEMATICA

Do[ If[ PrimeQ[2^n + 11], Print[n]], {n, 15250}] (* Robert G. Wilson v, Jan 21 2005 *)


PROG

(PARI) for(n=1, 9e9, ispseudoprime(2^n+11)&&print1(n", ")) \\ M. F. Hasler, Jul 18 2016


CROSSREFS

Cf. A094076.
Cf. A019434 (primes 2^n+1), A057732 (2^n+3), A059242 (2^n+5), A057195 (2^n+7), A057196(2^n+9), A102633 (this), A102634 (2^n+13), A057197 (2^n+15), A057200 (2^n+17), A057221 (2^n+19), A057201 (2^n+21), A057203 (2^n+23).
Sequence in context: A018388 A100866 A327823 * A052942 A240944 A117913
Adjacent sequences: A102630 A102631 A102632 * A102634 A102635 A102636


KEYWORD

nonn,hard,more


AUTHOR

Lei Zhou, Jan 20 2005


EXTENSIONS

a(18)  a(22) from Robert G. Wilson v, Jan 21 2005
a(23)  a(33) from Robert Price, Dec 06 2013
Edited by M. F. Hasler, Jul 18 2016


STATUS

approved



