A273942 Primes of the form 3^k + k.

11, 6569, 16677181699666603

Offset: 1

Author

Vincenzo Librandi, Jun 06 2016

Keywords

• nonn
• hard

Comments

Terms given correspond to k in A057900.

a(4) has 731 digits.

Links

• Amiram Eldar, Table of n, a(n) for n = 1..4

Crossrefs

Cf. A057900, A104743, A129962, A129963.

Programs

Magma

[a: n in [0..100] | IsPrime(a) where a is 3^n+n];

Mathematica

Select[Table[3^n + n, {n, 1, 1000}], PrimeQ]

Formula

a(n) = A104743(A057900(n)). - Amiram Eldar, Jul 27 2025