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A130784 Period 3: repeat [1, 3, 2]. 9
1, 3, 2, 1, 3, 2, 1, 3, 2, 1, 3, 2, 1, 3, 2, 1, 3, 2, 1, 3, 2, 1, 3, 2, 1, 3, 2, 1, 3, 2, 1, 3, 2, 1, 3, 2, 1, 3, 2, 1, 3, 2, 1, 3, 2, 1, 3, 2, 1, 3, 2, 1, 3, 2, 1, 3, 2, 1, 3, 2, 1, 3, 2, 1, 3, 2, 1, 3, 2, 1, 3, 2, 1, 3, 2, 1, 3, 2, 1, 3, 2, 1, 3, 2, 1, 3 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,2

COMMENTS

Continued fraction expansion of (3+sqrt(37))/7 (A176977). [Klaus Brockhaus, Apr 30 2010]

Pairwise sums of A010872(n). - Wesley Ivan Hurt, Jul 08 2014

Decimal expansion of 44/333. - David A. Corneth, Jul 02 2016

LINKS

Table of n, a(n) for n=0..85.

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

FORMULA

a(n) = (n mod 3) + ((n+1) mod 3). - Paolo P. Lava, Jul 18 2007

a(n) = 4 - n + 3 * floor((n-1)/3). - Wesley Ivan Hurt, Nov 30 2013

a(n) = A080425(n) + 1. - Wesley Ivan Hurt, Jul 08 2014

a(n) = 3 - (n+5 mod 3) = 1 + (-n mod 3). - Wesley Ivan Hurt, Aug 29 2014

a(n) = 3*a(n-1)^2/2 - 13*a(n-1)/2 + 8. - Robert Israel, Aug 29 2014

O.g.f.: (1+z)*(1+2*z)/(1-z^3). - Robert Israel, Aug 29 2014

E.g.f.: 2*exp(z) - 2/sqrt(3)*exp(-z/2)*cos(sqrt(3)*z/2+Pi/6). - Robert Israel, Aug 29 2014

a(n) = a(n-3) for n>2. - Wesley Ivan Hurt, Jul 02 2016

MAPLE

A130784:=n->4-n+3*floor((n-1)/3); seq(A130784(n), n=0..100); # Wesley Ivan Hurt, Nov 30 2013

MATHEMATICA

PadRight[{}, 111, {1, 3, 2}] (* Harvey P. Dale, Apr 20 2012 *)

CoefficientList[Series[(1 + 3 x + 2 x^2)/(1 - x^3), {x, 0, 120}], x] (* Michael De Vlieger, Jul 02 2016 *)

PROG

(PARI) a(n)=[1, 3, 2][n%3+1] \\ Charles R Greathouse IV, Jun 02 2011

(MAGMA) [(n mod 3) + ((n+1) mod 3) : n in [0..100]]; // Wesley Ivan Hurt, Jul 08 2014

CROSSREFS

Cf. A010872, A080425, A176977.

Sequence in context: A236966 A280048 A119910 * A138034 A229216 A087818

Adjacent sequences:  A130781 A130782 A130783 * A130785 A130786 A130787

KEYWORD

nonn,easy

AUTHOR

Paul Curtz, Jul 15 2007

STATUS

approved

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Last modified May 25 16:08 EDT 2017. Contains 287039 sequences.