A243437 Primes of the form 3^k + 16.

17, 19, 43, 97, 2203, 6577, 19699, 531457, 1594339, 14348923, 7625597485003, 617673396283963, 239299329230617529590099, 1570042899082081611640534579, 42391158275216203514294433217, 608266787713357709119683992618861323

Offset: 1

Author

Vincenzo Librandi, Jun 05 2014

Keywords

• nonn

Comments

Associated n: 0, 1, 3, 4, 7, 8, 9, 12, 13, 15, 27, 31, 49, 57, 60, 75, 139, 147, ...

Links

• Vincenzo Librandi, Table of n, a(n) for n = 1..28

Crossrefs

Cf. A000040, A205647 (corresponding k's).

Cf. Similar sequences listed in A102903.

Programs

Magma

[a: n in [0..200] | IsPrime(a) where a is 3^n+16];

Mathematica

Select[Table[3^n + 16, {n, 0, 500}], PrimeQ]

Formula

a(n) = 3^A205647(n) + 16. - Elmo R. Oliveira, Nov 11 2023