|
%I #17 Sep 08 2022 08:44:58
%S 19,37,73,577,1153,18433,147457,1179649,77309411329,39582418599937,
%T 79164837199873,83010348331692982273,332041393326771929089,
%U 1328165573307087716353,21760664753063325144711169,196002643346460554954903773880698489798657
%N Primes of the form 9*2^n+1.
%H Vincenzo Librandi, <a href="/A050528/b050528.txt">Table of n, a(n) for n = 1..25</a>
%H <a href="/index/Pri#riesel">Index entries for sequences of n such that k*2^n-1 (or k*2^n+1) is prime</a>
%p A050528:=n->`if`(isprime(9*2^n+1),9*2^n+1,NULL): seq(A050528(n), n=1..200); # _Wesley Ivan Hurt_, Aug 09 2014
%t Select[9*2^Range[150]+1,PrimeQ] (* _Harvey P. Dale_, Aug 08 2014 *)
%o (Magma) [a: n in [0..150] | IsPrime(a) where a is (9*2^n+1) ]; // _Vincenzo Librandi_, Aug 09 2014
%Y For more terms see A002256.
%K nonn
%O 1,1
%A _N. J. A. Sloane_, Dec 29 1999
| 