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A131289
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Period 12: repeat 1, 1, 3, -3, -3, 1, -1, -1, -3, 3, 3, -1.
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10
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1, 1, 3, -3, -3, 1, -1, -1, -3, 3, 3, -1, 1, 1, 3, -3, -3, 1, -1, -1, -3, 3, 3, -1, 1, 1, 3, -3, -3, 1, -1, -1, -3, 3, 3, -1, 1, 1, 3, -3, -3, 1, -1, -1, -3, 3, 3, -1, 1, 1, 3, -3, -3, 1, -1, -1, -3, 3, 3, -1, 1, 1, 3, -3, -3, 1, -1, -1, -3, 3, 3, -1, 1, 1, 3, -3, -3, 1, -1, -1, -3, 3, 3, -1, 1, 1, 3, -3, -3, 1, -1, -1, -3, 3, 3, -1, 1, 1, 3, -3, -3, 1
(list; graph; refs; listen; history; internal format)
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OFFSET
| 0,3
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LINKS
| Index to sequences with linear recurrences with constant coefficients, signature (0,0,0,0,0,-1).
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FORMULA
| a(n)=(1/6)*{-(n mod 12)+2*[(n+1) mod 12]-3*[(n+3) mod 12]+[(n+4) mod 12]+[(n+6) mod 12]-2*[(n+7) mod 12]+3*[(n+9) mod 12]-[(n+10) mod 12]}, with n>=0. - Paolo P. Lava (paoloplava(AT)gmail.com), Oct 08 2007
a(n) = 4*cos(Pi*n/6)/3 -2*sin(Pi*n/6)/3 -5*cos(Pi*n/2)/3 +5*sin(Pi*n/2)/3 +4*cos(5*Pi*n/6)/3 -2*sin(5*Pi*n/6)/3. R. J. Mathar, Oct 08 2011
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CROSSREFS
| Cf. A130974 (1, 1, 1, 3, 3, 3)
Sequence in context: A110566 A126066 A177693 * A130974 A064353 A190906
Adjacent sequences: A131286 A131287 A131288 * A131290 A131291 A131292
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KEYWORD
| sign,easy
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AUTHOR
| Paul Curtz (bpcrtz(AT)free.fr), Sep 29 2007
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EXTENSIONS
| More terms from Olaf Voss (richyfourtythree(AT)yahoo.com), Feb 11 2008
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