|
|
A104066
|
|
Primes of the form 2^k + 7.
|
|
21
|
|
|
11, 23, 71, 263, 1031, 65543, 262151, 1048583, 268435463, 1073741831, 274877906951, 17592186044423, 302231454903657293676551, 309485009821345068724781063, 316912650057057350374175801351
(list;
graph;
refs;
listen;
history;
text;
internal format)
|
|
|
OFFSET
|
1,1
|
|
COMMENTS
|
Also primes of the form 4^n+7 (in this case, the associated n are in A217349). - Bruno Berselli, Oct 03 2012
|
|
LINKS
|
|
|
FORMULA
|
|
|
MATHEMATICA
|
a = Delete[Union[Flatten[Table[If [PrimeQ[2^n + 7] == True, 2^ n + 7, 0], {n, 1, 400}]]], 1]
|
|
PROG
|
(Magma) [a: n in [0..100 by 2] | IsPrime(a) where a is 2^n+7]; // Vincenzo Librandi, Jan 26 2011
(PARI) list(lim)=my(v=List(), t); for(n=1, logint(lim\1-7, 4), if(ispseudoprime(t=4^n+7), listput(v, t))); Vec(v) \\ Charles R Greathouse IV, Nov 17 2017
|
|
CROSSREFS
|
|
|
KEYWORD
|
nonn
|
|
AUTHOR
|
|
|
STATUS
|
approved
|
|
|
|