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A131554
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Period 5: repeat 1 1 -1 1 -1.
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0
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1, 1, -1, 1, -1, 1, 1, -1, 1, -1, 1, 1, -1, 1, -1, 1, 1, -1, 1, -1, 1, 1, -1, 1, -1, 1, 1, -1, 1, -1, 1, 1, -1, 1, -1, 1, 1, -1, 1, -1, 1, 1, -1, 1, -1, 1, 1, -1, 1, -1, 1, 1, -1, 1, -1, 1, 1, -1, 1, -1, 1, 1, -1, 1, -1, 1, 1, -1, 1, -1
(list; graph; refs; listen; history; internal format)
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OFFSET
| 0,1
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FORMULA
| a(n)=(1/50)*{-19*(n mod 5)+21*[(n+1) mod 5]-19*[(n+2) mod 5]+21*[(n+3) mod 5]+[(n+4) mod 5]}, with n>=0 - Paolo P. Lava (paoloplava(AT)gmail.com), Aug 28 2007
G.f.: (-1-x+x^2-x^3+x^4)/(x-1)/(1+x+x^2+x^3+x^4). - R. J. Mathar (mathar(AT)strw.leidenuniv.nl), Nov 14 2007
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CROSSREFS
| Sequence in context: A121238 * A153881 A160357 A057077 A070748 A154990
Adjacent sequences: A131551 A131552 A131553 * A131555 A131556 A131557
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KEYWORD
| sign
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AUTHOR
| Paul Curtz (bpcrtz(AT)free.fr), Aug 26 2007
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