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A135447 Period 10: repeat [1, 2, 4, 8, 5, -1, -2, -4, -8, -5]. 1
1, 2, 4, 8, 5, -1, -2, -4, -8, -5, 1, 2, 4, 8, 5, -1, -2, -4, -8, -5, 1, 2, 4, 8, 5, -1, -2, -4, -8, -5, 1, 2, 4, 8, 5, -1, -2, -4, -8, -5, 1, 2, 4, 8, 5, -1, -2, -4, -8, -5, 1, 2, 4, 8, 5, -1, -2, -4, -8, -5, 1, 2, 4, 8, 5, -1, -2, -4, -8, -5, 1, 2, 4, 8, 5, -1, -2, -4, -8, -5, 1, 2, 4, 8 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,2

LINKS

Table of n, a(n) for n=0..83.

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

FORMULA

a(n+1) == 2*a(n) mod 11.

a(n) = (1/10)*(-6*(n mod 10)-3*((n+1) mod 10)+4*((n+2) mod 10)+2*((n+3) mod 10)+((n+4) mod 10)+6*((n+5) mod 10)+3*((n+6) mod 10)-4*((n+7) mod 10)-2*((n+8) mod 10)-((n+9) mod 10)), with n>=0. - Paolo P. Lava, Dec 18 2007

a(n) = (1/2 - (7*sqrt(5)/10))*cos(Pi*n/5) + (sqrt(2)/10)*(12*sqrt(5+sqrt(5))+7*sqrt(5-sqrt(5)))*sin(Pi*n/5) + (1/2 + (7*sqrt(5)/10))*cos(3*Pi*n/5) - (sqrt(2)/10)*(12*sqrt(5-sqrt(5)) - 7*sqrt(5+sqrt(5)))*sin(3*Pi*n/5). - Richard Choulet, Jan 04 2008

O.g.f.: (5*x^3+3*x^2+x+1)/(x^4-x^3+x^2-x+1). - R. J. Mathar, Jan 07 2008

a(n) = a(n-1)-a(n-2)+a(n-3)-a(n-4) for n>3. - Wesley Ivan Hurt, Sep 19 2015

MAPLE

A135447 := proc(n) op((n mod 10)+1, [1, 2, 4, 8, 5, -1, -2, -4, -8, -5]) ; end: seq(A135447(n), n=0..150) ; # R. J. Mathar, Feb 07 2009

MATHEMATICA

PadRight[{}, 100, {1, 2, 4, 8, 5, -1, -2, -4, -8, -5}] (* Vincenzo Librandi, Sep 19 2015 *)

PROG

(PARI) a(n)=[1, 2, 4, 8, 5, -1, -2, -4, -8, -5][n%10+1] \\ Charles R Greathouse IV, Jun 02 2011

(MAGMA) &cat[[1, 2, 4, 8, 5, -1, -2, -4, -8, -5]: n in [0..10]]; // Vincenzo Librandi, Sep 19 2015

CROSSREFS

Sequence in context: A126215 A165617 A273170 * A163339 A092892 A146079

Adjacent sequences:  A135444 A135445 A135446 * A135448 A135449 A135450

KEYWORD

sign,easy,less

AUTHOR

Paul Curtz, Dec 14 2007

EXTENSIONS

More periods from R. J. Mathar, Feb 07 2009

STATUS

approved

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Last modified December 3 01:12 EST 2016. Contains 278694 sequences.