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

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

Offset

1,1

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

Links

Table of n, a(n) for n=1..9.

Mathematica

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

Prog

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

Crossrefs

Cf. A058765, A082101, A161470.

Sequence in context: A081465 A381245 A128000 * A342606 A281312 A182313

Adjacent sequences: A161466 A161467 A161468 * A161470 A161471 A161472

Keyword

nonn

Author

Vladimir Joseph Stephan Orlovsky, Jun 10 2009

Extensions

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

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

Status

approved