A161469 Primes of the form 3^k + 2^k - k^3 + k^2.

2, 5, 17, 613, 129266611, 7625731683761, 150094704016430497, 2503155504994422192936289397051173, 4638397686588101984398752568803509060305779468709

Offset: 1

Author

Vladimir Joseph Stephan Orlovsky, Jun 10 2009

Keywords

• nonn

Comments

The associated values of k are 0, 1,3,6,17,27,36,70,102,237,377,463,576,639,683,... - R. J. Mathar, Jun 12 2009 [Amended by Harvey P. Dale, Jan 23 2023]

The next term (a(10)) has 114 digits. - Harvey P. Dale, Jan 23 2023

Crossrefs

Cf. A058765, A082101, A161470.

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

lst={};Do[If[PrimeQ[p=(3^n+2^n)-(n^3-n^2)],AppendTo[lst,p]],{n,0,6!}];lst
Select[Table[3^k+2^k-k^3+k^2,{k,0,200}],PrimeQ] (* Harvey P. Dale, Jan 23 2023 *)

Extensions

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

a(1) = 2 prepended by Harvey P. Dale, Jan 23 2023