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A080891 Period 5. +0
7
0, 1, -1, -1, 1, 0, 1, -1, -1, 1, 0, 1, -1, -1, 1, 0, 1, -1, -1, 1, 0, 1, -1, -1, 1, 0, 1, -1, -1, 1, 0, 1, -1, -1, 1, 0, 1, -1, -1, 1, 0, 1, -1, -1, 1, 0, 1, -1, -1, 1, 0, 1, -1, -1, 1, 0, 1, -1, -1, 1, 0, 1, -1, -1, 1, 0, 1, -1, -1, 1, 0, 1, -1, -1, 1, 0, 1, -1, -1, 1, 0, 1, -1, -1, 1, 0, 1, -1, -1, 1, 0, 1, -1, -1, 1, 0, 1, -1, -1, 1, 0 (list; graph; listen)
OFFSET

0,1

COMMENT

a(n) = (5/n), where (k/n) is the Kronecker symbol.

L(1;5) (Dirichlet L-series) is the integral from 0 to 1 of the g.f. of a(n+1). Partial sums are A092202. - Paul Barry (pbarry(AT)wit.ie), Apr 01 2005

REFERENCES

H. Cohn, Advanced Number Theory, Dover Publications, Inc., 1962, p. 173.

LINKS

J.-P. Serre, On a theorem of Jordan, Bull. Amer. Math. Soc., 40 (No. 4, 2003), 429-440, see p. 435.

Eric Weisstein's World of Mathematics, Kronecker Symbol

Index entries for two-way infinite sequences

FORMULA

If n==0 (mod 5) a(n)=0; if n==1 or 4 (mod 5) a(n)=1; if n==2 or 3 (mod 5) a(n)=-1.

G.f.: x(1-x^2)/(1+x+x^2+x^3+x^4); - Paul Barry (pbarry(AT)wit.ie), Apr 01 2005

G.f.: x(1-x)(1-x^2)/(1-x^5). a(n+5)=a(-n)=a(n).

Euler transform of length 5 sequence [ -1, -1, 0, 0, 1]. - Michael Somos, Jun 17 2005

Transform of the Fibonacci numbers by the Riordan array A102587. - Paul Barry (pbarry(AT)wit.ie), Jul 14 2005

a(n)=1/5*{n mod 5-2*[(n+1) mod 5]+2*[(n+3) mod 5]-[(n+4) mod 5]} - Paolo P. Lava (ppl(AT)spl.at), Oct 20 2006

PROGRAM

(PARI) a(n)=kronecker(5, n) [Also, a(n)=kronecker(n, 5) ]

(PARI) a(n)=(n^2+1)%5-1 /* Michael Somos Dec 01 2004 */

(Mupad) numlib::jacobi(n, 5)$ n=0..100 - Zerinvary Lajos (zerinvarylajos(AT)yahoo.com), May 13 2008

CROSSREFS

Cf. A086937.

Sequence in context: A106743 A011558 A100047 this_sequence A112713 A143536 A080110

Adjacent sequences: A080888 A080889 A080890 this_sequence A080892 A080893 A080894

KEYWORD

sign,mult

AUTHOR

N. J. A. Sloane (njas(AT)research.att.com), Sep 23 2003

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Last modified November 24 23:16 EST 2009. Contains 167481 sequences.


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