A102903 Primes of the form 3^k + 4.

5, 7, 13, 31, 733, 19687, 59053, 31381059613, 205891132094653, 109418989131512359213, 1570042899082081611640534567, 323257909929174534292273980721360271853391

Offset: 1

Author

Roger L. Bagula, Mar 01 2005

Keywords

• nonn

Links

• Vincenzo Librandi, Table of n, a(n) for n = 1..17

Crossrefs

Cf. A000040, A058958 (associated k).

Cf. Primes of the form 3^k + d: A057735 (d=2), this sequence (d=4), A102870 (d=8), A102907 (d=10), A102874 (d=14), A243437 (d=16), A102904 (d=20), A243438 (d=22), A243439 (d=26), A102906 (d=28).

Programs

Magma

[a: n in [0..100] | IsPrime(a) where a is 3^n+4]; // Vincenzo Librandi, Jul 19 2012

Mathematica

Select[Table[3^n+4,{n,0,200}],PrimeQ] (* Vincenzo Librandi, Jul 19 2012 *)

Formula

a(n) = 3^A058958(n) + 4. - Elmo R. Oliveira, Nov 09 2023

Extensions

Edited by Zak Seidov, Aug 29 2014