A131670 Period 5: repeat [1, 0, -1, 0, 1].

1, 0, -1, 0, 1, 1, 0, -1, 0, 1, 1, 0, -1, 0, 1, 1, 0, -1, 0, 1, 1, 0, -1, 0, 1, 1, 0, -1, 0, 1, 1, 0, -1, 0, 1, 1, 0, -1, 0, 1, 1, 0, -1, 0, 1, 1, 0, -1, 0, 1, 1, 0, -1, 0, 1, 1, 0, -1, 0, 1, 1, 0, -1, 0, 1, 1, 0, -1, 0, 1, 1, 0, -1, 0, 1, 1, 0, -1, 0, 1, 1, 0, -1, 0, 1, 1, 0, -1, 0, 1, 1, 0, -1, 0, 1, 1, 0, -1, 0, 1, 1, 0, -1, 0, 1, 1, 0, -1, 0, 1, 1, 0, -1, 0, 1, 1, 0

Offset

0,1

Links

Muniru A Asiru, Table of n, a(n) for n = 0..2000

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

Formula

G.f.: ( -1+x^2-x^4 ) / ( (x-1)*(1+x+x^2+x^3+x^4) ). - R. J. Mathar, Apr 02 2011

a(n) = (2/5)*(1/2 + cos(4*(n-4)*Pi/5) - cos(2*(n-2)*Pi/5) - cos(4*(n-2)*Pi/5) + cos(2*n*Pi/5) + cos(4*n*Pi/5) + cos(2*(n+1)*Pi/5)). - Wesley Ivan Hurt, Sep 26 2018

Maple

seq(op([1, 0, -1, 0, 1]), n=1..30); # Muniru A Asiru, Sep 29 2018

Mathematica

PadRight[{}, 120, {1, 0, -1, 0, 1}]  (* Harvey P. Dale, May 22 2012 *)

Prog

(PARI) a(n)=abs(n%5-2)-1 \\ Jaume Oliver Lafont, Aug 28 2009
(GAP) Flat(List([1..30], n->[1, 0, -1, 0, 1])); # Muniru A Asiru, Sep 29 2018
(Magma) &cat[[1, 0, -1, 0, 1]^^20]; // Vincenzo Librandi, Oct 02 2018

Crossrefs

Sequence in context: A341150 A244220 A283963 * A188044 A287523 A288932

Adjacent sequences: A131667 A131668 A131669 * A131671 A131672 A131673

Keyword

sign,easy

Author

Paul Curtz, Oct 03 2007

Status

approved