

A118480


(nth 4k+1 prime minus nth 4k+3 prime less two)/4.


1



0, 1, 1, 2, 3, 2, 2, 3, 3, 5, 6, 5, 6, 2, 7, 5, 6, 8, 7, 7, 7, 12, 10, 10, 11, 11, 12, 10, 10, 12, 11, 13, 10, 10, 10, 10, 9, 8, 7, 9, 3, 4, 4, 4, 11, 13, 15, 17, 19, 19, 22, 19, 16, 13, 17, 16, 15, 16, 14, 17, 16, 21, 24, 19, 19, 13, 17, 17, 19, 19, 16, 11, 13, 13, 22, 19, 19, 17, 22
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OFFSET

1,4


COMMENTS

Zero occurs infinitely often as do the negative numbers.
First occurrence of a(n) beginning with 0: 1, 2, 4, 5, 42, 10, 11, 15, 18, 37, 23, 25, 22, 32, 59, 47, 53, 48, 83, 49, 110, 62, 51, 82, 63, 170, ...,
The first negative term is at n=1473.  T. D. Noe, Apr 09 2009


LINKS

T. D. Noe, Table of n, a(n) for n=1..2000


FORMULA

(A002144(n)  A002145(n)  2)/4.


MATHEMATICA

(Select[1 + 4Range@245, PrimeQ@# &]  Select[ 1 + 4Range@225, PrimeQ@# &]  2)/4


CROSSREFS

Cf. A022757, A007350, A007351, A038691.
Sequence in context: A242789 A076733 A079643 * A104377 A109337 A303539
Adjacent sequences: A118477 A118478 A118479 * A118481 A118482 A118483


KEYWORD

sign


AUTHOR

Clark Kimberling and Robert G. Wilson v, May 04 2006


STATUS

approved



