A161470 Primes of the form 3^k+2^k+k^3-k^2.

5, 17, 53, 2609, 1604543, 7625731721669, 67585198634826967968486182915129003

Offset: 1

Author

Vladimir Joseph Stephan Orlovsky, Jun 10 2009

Keywords

• nonn

Comments

The associated k are 1, 2, 3, 7, 13, 27, 73, 994, 1129, ... - R. J. Mathar, Jun 12 2009

The next term has 475 digits. - Harvey P. Dale, Dec 12 2010

Crossrefs

Cf. A058765, A082101, A161469.

Programs

Magma

[ a: n in [1..450] | IsPrime(a) where a is 3^n+2^n+n^3-n^2] // Vincenzo Librandi, Nov 30 2010

Mathematica

A161470 = {}; Do[If[PrimeQ[p = (3^n + 2^n) + (n^3 - n^2)], AppendTo[A161470, p]], {n, 6!}]; A161470 (* Orlovsky *)
(* Alternate: *) Select[Table[3^k + 2^k + k^3 - k^2, {k, 2000}], PrimeQ] (* Harvey P. Dale, Dec 12 2010 *)

Extensions

Definition simplified by R. J. Mathar, Jun 12 2009