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

2, 5, 188286357631, 15018933029959449607893431916515023, 1643356469972045002664087635582629208716484341598400533

Offset

1,1

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

Links

Table of n, a(n) for n=1..5.

Example

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

Mathematica

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

Prog

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

Crossrefs

Sequence in context: A325957 A247148 A139062 * A340984 A122760 A358029

Adjacent sequences: A241858 A241859 A241860 * A241862 A241863 A241864

Keyword

nonn

Author

Juri-Stepan Gerasimov, Apr 30 2014

Status

approved