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A131290 1 followed by period 6: repeat [3, 2, 0, -1, 0, 2]. 2
1, 3, 2, 0, -1, 0, 2, 3, 2, 0, -1, 0, 2, 3, 2, 0, -1, 0, 2, 3, 2, 0, -1, 0, 2, 3, 2, 0, -1, 0, 2, 3, 2, 0, -1, 0, 2, 3, 2, 0, -1, 0, 2, 3, 2, 0, -1, 0, 2, 3, 2, 0, -1, 0, 2, 3, 2, 0, -1, 0, 2, 3, 2, 0, -1, 0, 2, 3, 2, 0, -1, 0, 2, 3, 2, 0, -1, 0, 2, 3, 2, 0, -1, 0, 2, 3, 2, 0, -1, 0, 2, 3, 2, 0, -1, 0, 2, 3, 2, 0, -1 (list; graph; refs; listen; history; text; internal format)
OFFSET
0,2
LINKS
FORMULA
G.f.: (1+x-2*x^2+x^3)/((1-x)*(1-x+x^2)). - R. J. Mathar, Feb 27 2008
If n mod 6 = 4 then a(n) = (Fibonacci(n-3)*Fibonacci(n+1)) mod 4 -2, else a(n) = (Fibonacci(n-3)*Fibonacci(n+1)) mod 4, n>0. - Gary Detlefs, Dec 12 2010
From Wesley Ivan Hurt, Jun 20 2016: (Start)
a(n) = 2*a(n-1) - 2*a(n-2) + a(n-3) for n>4.
a(0) = 1, a(n) = 1 + cos(n*Pi/3) + sqrt(3)*sin(n*Pi/3) for n>0. (End)
MAPLE
A131290 := proc(n) if n = 0 then 1; else op(((n-1)mod 6)+1, [3, 2, 0, -1, 0, 2]) ; fi ; end: seq(A131290(n), n=0..100) ; # R. J. Mathar, Feb 27 2008
MATHEMATICA
PadRight[{1}, 110, {2, 3, 2, 0, -1, 0}] (* or *) Join[{1}, LinearRecurrence[ {2, -2, 1}, {3, 2, 0}, 110]] (* Harvey P. Dale, Jun 22 2012 *)
PROG
(Magma) [1] cat &cat [[3, 2, 0, -1, 0, 2]^^30]; // Wesley Ivan Hurt, Jun 20 2016
CROSSREFS
Sequence in context: A187145 A285700 A290693 * A138741 A116604 A303913
KEYWORD
sign,easy
AUTHOR
Paul Curtz, Sep 29 2007
EXTENSIONS
More terms from R. J. Mathar, Feb 27 2008
STATUS
approved

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Last modified March 28 16:05 EDT 2024. Contains 371254 sequences. (Running on oeis4.)