A057733 - OEIS

%I #34 Nov 08 2023 06:22:49

%S 5,7,11,19,67,131,4099,32771,65539,262147,268435459,1073741827,

%T 36028797018963971,147573952589676412931,19342813113834066795298819,

%U 431359146674410236714672241392314090778194310760649159697657763987459

%N Primes of the form 2^k + 3.

%H Robert Israel, <a href="/A057733/b057733.txt">Table of n, a(n) for n = 1..25</a>

%F a(n) = 2^A057732(n) + 3. - _Elmo R. Oliveira_, Nov 08 2023

%p for n from 1 to 2000 do `if`(isprime(2^n + 3), 2^n + 3, NULL) od;

%p # alternative:

%p select(isprime, [seq(2^n+3,n=1..2000)]); # _Robert Israel_, Dec 28 2015

%t Select[Table[2^n + 3, {n, 230}], PrimeQ] (* _Jayanta Basu_, May 23 2013 *)

%o (Magma) [ a: n in [0..250] | IsPrime(a) where a is 2^n+3 ] // _Vincenzo Librandi_, Aug 07 2010

%o (PARI) for(n=1,99,if(ispseudoprime(t=2^n+3),print1(t", "))) \\ _Charles R Greathouse IV_, Jul 02 2013

%Y Cf. A000040, A057732.

%K nonn

%O 1,1

%A _G. L. Honaker, Jr._, Oct 29 2000

%E More terms from Francois Jooste (pin(AT)myway.com), Mar 17 2003