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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 sequences related to linear recurrences with constant coefficients, signature (1,-1,1,-1).

FORMULA

a(n+1) == 2a(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) = (0.5-(7*5^0.5/10))*cos(Pi*n/5)+(2^0.5/10)*(12*(5+5^0.5)^0.5+7*(5-5^0.5)^0.5)*sin(Pi*n/5)+(0.5+(7*5^0.5/10))*cos(3*Pi*n/5)-(2^0.5/10)*(12*(5-5^0.5)^0.5-7*(5+5^0.5)^0.5)*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

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) ; [From R. J. Mathar, Feb 07 2009]

PROG

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

CROSSREFS

Sequence in context: A133992 A126215 A165617 * 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 September 2 12:10 EDT 2014. Contains 246357 sequences.