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A117808 Primes of the form floor(((2 + sqrt(3))^n + (2 - sqrt(3))^n)/4). 2

%I

%S 3,13,181,2521,489061,6811741,1321442641,18405321661,

%T 381765135195632792959100810331957408101589361

%N Primes of the form floor(((2 + sqrt(3))^n + (2 - sqrt(3))^n)/4).

%C Gaukman sequence from Mathworld Mathematica notebook.

%C Primes among absolute values of A108946.

%D Eric Weisstein. "Prime-Generating Polynomial." http://mathworld.wolfram.com/Prime-GeneratingPolynomial.html

%t a=Expand[Table[(((2 + Sqrt[3])^#1 + (2 - Sqrt[3])^#1)/4 & )[Prime[n]], {n, 10}]] Floor[a]

%K nonn

%O 1,1

%A _Roger L. Bagula_, Apr 29 2006

%E Definition and terms corrected by _N. J. A. Sloane_, May 21, 2010

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Last modified May 22 21:05 EDT 2019. Contains 323503 sequences. (Running on oeis4.)