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A111915 Expansion of -x^2*(x-1)*(x^2-x+1)*(x+x^2+1)/(1-x^4+x^8). 3
0, 0, 1, -1, 1, -1, 2, -2, 1, -1, 1, -1, 0, 0, -1, 1, -1, 1, -2, 2, -1, 1, -1, 1, 0, 0, 1, -1, 1, -1, 2, -2, 1, -1, 1, -1, 0, 0, -1, 1, -1, 1, -2, 2, -1, 1, -1, 1, 0, 0, 1, -1, 1, -1, 2, -2, 1, -1, 1, -1, 0, 0, -1, 1, -1, 1, -2, 2, -1, 1, -1, 1, 0, 0, 1, -1, 1, -1, 2, -2, 1, -1, 1, -1, 0, 0, -1, 1, -1, 1, -2, 2, -1, 1, -1, 1, 0, 0, 1, -1 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,7

COMMENTS

It appears that a(n) has period 24.

This is true, as (1-x^4+x^8) is the cyclotomic polynomial for n=24. - Joerg Arndt, Feb 03 2017

LINKS

Table of n, a(n) for n=0..99.

Index entries for linear recurrences with constant coefficients, signature (0,0,0,1,0,0,0,-1).

FORMULA

G.f.: -x^2*(x-1)*(x^2-x+1)*(x+x^2+1)/(1-x^4+x^8).

MATHEMATICA

CoefficientList[Series[-x^2*(x - 1)*(x^2 - x + 1)*(x + x^2 + 1)/(1 - x^4 + x^8), {x, 0, 100}], x] (* Wesley Ivan Hurt, Feb 03 2017 *)

PROG

(PARI) a(n)=[0, 0, 1, -1, 1, -1, 2, -2, 1, -1, 1, -1, 0, 0, -1, 1, -1, 1, -2, 2, -1, 1, -1, 1][n%24+1] \\ Charles R Greathouse IV, Feb 03 2017

CROSSREFS

Cf. A085846, A111912, A111913, A111914.

Sequence in context: A234514 A051031 A181059 * A066520 A088526 A054535

Adjacent sequences:  A111912 A111913 A111914 * A111916 A111917 A111918

KEYWORD

easy,less,sign

AUTHOR

Creighton Dement, Aug 20 2005

STATUS

approved

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Last modified November 19 01:45 EST 2017. Contains 294912 sequences.