A052289 Numbers n such that n!*2^n + n + 1 = A000165(n) + n + 1 is prime.

0, 2, 4, 12, 18, 36

Offset

1,2

Comments

For comparison, A000165(n)+1 is prime for n = 0, 1, 259, 16708, 18655,... (A256594).

a(6) > 25000, if it exists. - Giovanni Resta, Jun 01 2018

Links

Table of n, a(n) for n=1..6.

Example

n=4, 2^4*4! + 4 + 1 = 389 is prime.

Mathematica

Select[Range[100], PrimeQ[#! 2^# + # + 1] &] (* Giovanni Resta, May 31 2018 *)

Crossrefs

Cf. A000165, A052290, A256594.

Sequence in context: A064407 A309519 A198392 * A309547 A309552 A309626

Adjacent sequences: A052286 A052287 A052288 * A052290 A052291 A052292

Keyword

nonn,more

Author

Labos Elemer, Feb 08 2000

Extensions

a(1)=0 inserted by Sean A. Irvine, Nov 03 2021

Status

approved