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A200816
Numbers k such that (2^k - k)*2^k + 1 is prime.
7
1, 3, 4, 10, 11, 16, 47, 57, 69, 166, 327, 460, 1108, 4740, 20760, 21143, 27779, 34293, 34311
OFFSET
1,2
COMMENTS
The generalization of this sequence is possible with the primes of the form (b^n +- k)*b^n +- 1.
EXAMPLE
4 is in the sequence because (2^4 - 4)*2^4 + 1 = 193 is prime.
MATHEMATICA
lst={}; Do[If[PrimeQ[(2^n - n)*2^n+1], AppendTo[lst, n]], {n, 10^3}]; lst
PROG
(PARI) is(n)=ispseudoprime((2^n-n)<<n+1) \\ Charles R Greathouse IV, Feb 17 2017
KEYWORD
nonn,more
AUTHOR
Michel Lagneau, Nov 23 2011
EXTENSIONS
a(17)-a(19) from Michael S. Branicky, Jul 14 2023
STATUS
approved