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A173950 a(n)= 1 if 6 |  prime(n)+1, a(n) = -1 if 6 | prime(n)-1, a(n) = 0 otherwise. 2
0, 0, 1, -1, 1, -1, 1, -1, 1, 1, -1, -1, 1, -1, 1, 1, 1, -1, -1, 1, -1, -1, 1, 1, -1, 1, -1, 1, -1, 1, -1, 1, 1, -1, 1, -1, -1, -1, 1, 1, 1, -1, 1, -1, 1, -1, -1, -1, 1, -1, 1, 1, -1, 1, 1, 1, 1, -1, -1, 1, -1, 1, -1, 1, -1, 1, -1, -1, 1, -1, 1, 1, -1, -1, -1, 1, 1, -1, 1, -1, 1, -1, 1, -1, -1, 1, 1, -1, 1, -1, 1, 1, -1, 1, -1, 1, 1, 1, -1, -1 (list; graph; refs; listen; history; text; internal format)
OFFSET

1

COMMENTS

Equals -A134323 except for the first term. - M. F. Hasler, Oct 09 2011

LINKS

Table of n, a(n) for n=1..100.

FORMULA

a(n)=-A134323(n) for n>1. - M. F. Hasler, Oct 09 2011

PROG

(PARI) (Contribution by M. F. Hasler, Oct 09 2011) (Start)

A173950(n)=if(prime(n)%6==1, -1, n>2)

A173950(n)=(-1)^(prime(n)%3)*(n>2)

A173950(n)=[-1, 0, 0, 0, 1][prime(n)%6]

A173950(n)=if(n>2, prime(n)%6-3)/2  \\ (End)

CROSSREFS

Cf. A132194, A099618, A134323, A112632, A096630, A007352, A098044.

Sequence in context: A288226 A189078 A257834 * A283020 A284683 A288673

Adjacent sequences:  A173947 A173948 A173949 * A173951 A173952 A173953

KEYWORD

sign

AUTHOR

Giovanni Teofilatto, Nov 26 2010

STATUS

approved

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Last modified December 12 16:38 EST 2017. Contains 295949 sequences.