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A052289
Numbers n such that n!*2^n + n + 1 = A000165(n) + n + 1 is prime.
1
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
EXAMPLE
n=4, 2^4*4! + 4 + 1 = 389 is prime.
MATHEMATICA
Select[Range[100], PrimeQ[#! 2^# + # + 1] &] (* Giovanni Resta, May 31 2018 *)
CROSSREFS
KEYWORD
nonn,more
AUTHOR
Labos Elemer, Feb 08 2000
EXTENSIONS
a(1)=0 inserted by Sean A. Irvine, Nov 03 2021
STATUS
approved