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A226915 Fourth column of A226518. 2
-1, 1, 1, 1, 1, -1, 3, -1, 1, 1, 1, -1, 3, -1, 1, 1, -1, 3, 3, 1, 1, 1, 3, -1, 1, 1, 1, 1, 1, 1, 1, -1, -1, 1, 1, -1, 3, -1, 1, 1, 3, 3, -1, 1, -1, 1, 1, 1, 1, 3, 3, 1, 1, 3, -1, 1, 1, 1, -1, -1, -1, 3, 3, -1, -1, 3, 1, 1, 1, 3, 1, 1, -1, 3, -1, 1, 1, 3, 1, 1, 3, 3, 1, 1, 1, 3, -1, 1, 1, 3, 1, 1, -1, 3, -1, 1 (list; graph; refs; listen; history; text; internal format)
OFFSET

3,7

LINKS

Table of n, a(n) for n=3..98.

FORMULA

a(n) = 1 + Legendre(2,p) + Legendre(3,p) where p = prime(n).

CROSSREFS

Cf. A226518.

Sequence in context: A272334 A014491 A214071 * A180173 A318668 A322361

Adjacent sequences:  A226912 A226913 A226914 * A226916 A226917 A226918

KEYWORD

sign

AUTHOR

N. J. A. Sloane, Jun 22 2013

STATUS

approved

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Last modified July 2 08:02 EDT 2020. Contains 335398 sequences. (Running on oeis4.)