A241861 Primes of the form 2*3^k - k.

2, 5, 188286357631, 15018933029959449607893431916515023, 1643356469972045002664087635582629208716484341598400533

Offset: 1

Author

Juri-Stepan Gerasimov, Apr 30 2014

Keywords

• nonn

Comments

Generated by k = 0, 1, 23, 71, 113,.. - Michel Marcus, May 11 2014

No other terms for k < 100000. - Jens Kruse Andersen, May 19 2014

Examples

			2 is in this sequence because 2*3^0 - 0 = 2.
		

Programs

Magma

[a: n in [0..150] | IsPrime(a) where a is 2*3^n - n]; // Juri-Stepan Gerasimov, Apr 30 2014

Mathematica

Select[Table[2 3^n - n, {n, 0, 300}], PrimeQ] (* Vincenzo Librandi, Oct 21 2014 *)