login
Average of twin-prime pairs modulo 5.
0

%I #4 Dec 18 2013 18:28:16

%S -1,1,2,-2,0,2,0,2,2,-2,-2,0,0,2,-2,-2,0,0,2,2,-2,0,2,2,2,0,0,-2,2,0,

%T 0,2,-2,-2,2,0,2,0,2,2,2,0,-2,0,2,0,-2,2,2,-2,-2,0,-2,-2,2,-2,2,-2,2,

%U 0,-2,-2,2,-2,2,0,2,-2,-2,0,0,2,0,2,-2,-2,2,0,0,2,0,0,0,-2,2,-2,0,0,0,2,0,2,-2,-2,0,-2,2,2,-2,2,2,-2,0,2,0,0,2,-2,-2,-2,0

%N Average of twin-prime pairs modulo 5.

%e First twin-prime average = 4 (=-1+1*5): a(1) = -1.

%e Second twin-prime average = 6 (=1+1*5): a(2) = +1.

%e Third twin-prime average = 12 (=2+2*5): a(3) = +2.

%t Mod[#,5]&/@(Mean/@Select[Partition[Prime[Range[1000]],2,1], Last[#]- First[#]==2&])/.{4->-1,3->-2} (* _Harvey P. Dale_, Dec 18 2013 *)

%Y Cf. A014574.

%K sign

%O 1,3

%A _Greg Huber_, Jul 18 2006