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Primes of the form 2^x+x+y+2^y, with x and y integers of any sign.
3

%I #5 Mar 31 2012 12:38:25

%S 2,7,17,23,31,43,71,73,107,541,2129,4111,4243,9239,18457,32789,32803,

%T 65563,65687,73757,135197,147487,264221,589859,786469,1048633,1049117,

%U 4194329,4194847,4227109,8388637,8392739,8405029,8650793,16908329

%N Primes of the form 2^x+x+y+2^y, with x and y integers of any sign.

%e a(1) = A006127(1)+A006127(1) =2. a(2) = A006127(1)+A006127(3)=7.

%e a(3) = A006127(4)+A006127(3) =17. a(4) = A006127(5)+A006127(2) = 23.

%t f[x_,y_]:=2^x+x+y+2^y; lst={};Do[Do[p=f[x,y];If[PrimeQ[p],AppendTo[lst, p]],{y,-5!,6!}],{x,-5!,6!}];Take[Union[lst],5! ]

%Y Cf. A162573, A006127.

%K nonn

%O 1,1

%A _Vladimir Joseph Stephan Orlovsky_, Jul 06 2009

%E Examples added by _R. J. Mathar_, Sep 17 2009