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A132677
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Triperiodic or period 3: repeat 1, 2, -3.
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1
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1, 2, -3, 1, 2, -3, 1, 2, -3, 1, 2, -3, 1, 2, -3, 1, 2, -3, 1, 2, -3, 1, 2, -3, 1, 2, -3, 1, 2, -3, 1, 2, -3, 1, 2, -3, 1, 2, -3, 1, 2, -3, 1, 2, -3, 1, 2, -3, 1, 2, -3, 1, 2, -3, 1, 2, -3, 1, 2, -3, 1, 2, -3, 1, 2, -3, 1, 2, -3, 1, 2, -3, 1, 2, -3, 1, 2, -3, 1, 2, -3, 1, 2, -3, 1, 2, -3, 1, 2, -3, 1, 2, -3, 1, 2, -3, 1, 2, -3
(list; graph; refs; listen; history; internal format)
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OFFSET
| 0,2
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LINKS
| Index to sequences with linear recurrences with constant coefficients, signature (-1,-1).
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FORMULA
| Sequence proportional to its 6n-th differences.
a(n)=(1/3)*{-4*(n mod 3)+5*[(n+1) mod 3]-[(n+2) mod 3]} - Paolo P. Lava (paoloplava(AT)gmail.com), Nov 30 2007
G.f.: (1+3*x)/(1+x+x^2) [From Jaume Oliver Lafont (joliverlafont(AT)gmail.com), Mar 24 2009]
a(n) = cos(2*Pi*n/3)+5*sin(2*Pi*n/3)/sqrt(3). - R. J. Mathar, Oct 08 2011
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PROG
| (PARI) a(n)=[1, 2, -3][1+n%3] [From Jaume Oliver Lafont (joliverlafont(AT)gmail.com), Mar 24 2009]
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CROSSREFS
| Cf. A049347, A000748, A101544.
Sequence in context: A179542 A082846 A117373 * A010882 A106590 A194074
Adjacent sequences: A132674 A132675 A132676 * A132678 A132679 A132680
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KEYWORD
| sign,easy
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AUTHOR
| Paul Curtz (bpcrtz(AT)free.fr), Nov 15 2007
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