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A120439 Average of twin-prime pairs modulo 5. 0
-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, 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, 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 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,3

LINKS

Table of n, a(n) for n=1..111.

EXAMPLE

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

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

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

MATHEMATICA

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

CROSSREFS

Cf. A014574.

Sequence in context: A122157 A080378 A243865 * A248512 A352564 A353596

Adjacent sequences: A120436 A120437 A120438 * A120440 A120441 A120442

KEYWORD

sign

AUTHOR

Greg Huber, Jul 18 2006

STATUS

approved

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Last modified January 27 21:49 EST 2023. Contains 359849 sequences. (Running on oeis4.)