login
The OEIS is supported by the many generous donors to the OEIS Foundation.

 

Logo
Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A120491 Numbers k such that 22*3^k + 1 is prime. 0

%I #16 Jul 14 2023 15:12:48

%S 0,1,2,4,5,10,12,14,24,34,37,52,56,65,68,96,106,128,156,169,236,254,

%T 481,618,641,672,700,774,1274,1625,1841,4650,6030,8372,8760,9173,

%U 12776,13873,25214,25548,33834

%N Numbers k such that 22*3^k + 1 is prime.

%e If k=96 then 22*3^k + 1 is a prime with 48 digits.

%t Select[Range[0, 2000], PrimeQ[22*3^# + 1] &] (* _Stefan Steinerberger_, Aug 06 2006 *)

%o (Magma) [ n: n in [0..3000] | IsPrime(22*3^n + 1) ] // _Vincenzo Librandi_, Jan 31 2011

%o (PARI) is(n)=ispseudoprime(22*3^n+1) \\ _Charles R Greathouse IV_, Jun 13 2017

%Y Cf. A003306.

%K nonn,more

%O 1,3

%A _Parthasarathy Nambi_, Aug 04 2006

%E More terms from _Stefan Steinerberger_, Aug 06 2006

%E a(32)-a(41) from _Michael S. Branicky_, Jul 14 2023

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recents
The OEIS Community | Maintained by The OEIS Foundation Inc.

License Agreements, Terms of Use, Privacy Policy. .

Last modified July 28 14:06 EDT 2024. Contains 374697 sequences. (Running on oeis4.)