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A131670
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Period 5: repeat 1, 0, -1, 0, 1.
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0
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1, 0, -1, 0, 1, 1, 0, -1, 0, 1, 1, 0, -1, 0, 1, 1, 0, -1, 0, 1, 1, 0, -1, 0, 1, 1, 0, -1, 0, 1, 1, 0, -1, 0, 1, 1, 0, -1, 0, 1, 1, 0, -1, 0, 1, 1, 0, -1, 0, 1, 1, 0, -1, 0, 1, 1, 0, -1, 0, 1, 1, 0, -1, 0, 1, 1, 0, -1, 0, 1, 1, 0, -1, 0, 1, 1, 0, -1, 0, 1, 1, 0, -1, 0, 1, 1, 0, -1, 0, 1, 1, 0, -1, 0, 1, 1, 0, -1, 0, 1, 1, 0, -1, 0, 1, 1, 0, -1, 0, 1, 1, 0, -1, 0, 1, 1, 0
(list; graph; refs; listen; history; internal format)
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OFFSET
| 0,1
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LINKS
| Index to sequences with linear recurrences with constant coefficients, signature (0,0,0,0,1)
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FORMULA
| a(n)=(1/50)*{(n mod 5)-9*[(n+1) mod 5]-9*[(n+2) mod 5]+11*[(n+3) mod 5]+11*[(n+4) mod 5]}, with n>=0 - Paolo P. Lava (paoloplava(AT)gmail.com), Oct 24 2007
G.f. ( -1+x^2-x^4 ) / ( (x-1)*(1+x+x^2+x^3+x^4) ). - R. J. Mathar, Apr 02 2011
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PROG
| (PARI) a(n)=abs(n%5-2)-1 [From Jaume Oliver Lafont (joliverlafont(AT)gmail.com), Aug 28 2009]
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CROSSREFS
| Sequence in context: A176330 A177990 A113704 * A155482 A174205 A114483
Adjacent sequences: A131667 A131668 A131669 * A131671 A131672 A131673
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KEYWORD
| sign,easy
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AUTHOR
| Paul Curtz (bpcrtz(AT)free.fr), Oct 03 2007
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