A120438 Average of twin-prime pairs modulo 10 (least absolute residue).

4, -4, 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

Offset

1,1

Comments

All terms after a(2) are 0, 2, or -2. - Franklin T. Adams-Watters, Aug 27 2012

Links

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

Example

First twin-prime average = (3+5)/2 = 4: a(1) = +4.
Second twin-prime average = (5+7)/2 = 6 (= -4+1*10): a(2) = -4.
Third twin-prime average = (11+13)/2 = 12 (= 2+1*10): a(3) = +2.

Crossrefs

Cf. A014574.

Sequence in context: A182781 A291085 A193556 * A366470 A192977 A038800

Adjacent sequences: A120435 A120436 A120437 * A120439 A120440 A120441

Keyword

sign

Author

Greg Huber, Jul 18 2006

Extensions

Edited by Franklin T. Adams-Watters, Aug 27 2012

Status

approved