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A140342
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a(n)=5a(n-1)-11a(n-2)+13a(n-3)-9a(n-4)+3a(n-5)-a(n-6).
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3
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0, 0, 0, 0, 0, 1, 5, 14, 28, 42, 42, 0, -131, -417, -924, -1652, -2380, -2380, 0, 7753, 25213, 56714, 102256, 147798, 147798, 0, -479779, -1557649, -3499720, -6305992, -9112264, -9112264, 0, 29587889, 96072133, 215873462, 388991876, 562110290, 562110290, 0
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OFFSET
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0,7
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COMMENTS
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This is the main sequence representing the degenerate case of sequences which equal their seventh difference, where besides the generic a(n)=7a(n-1)-21(n-2)+35a(n-3)-35a(n-4)+21a(n-5)-7a(n-6)+2a(n-7), cf. A135356, there is also a shorter recurrence.
After the first four terms, every seventh term is zero. - Harvey P. Dale, Sep 20 2012
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LINKS
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FORMULA
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O.g.f.: x^5/(1-5x+11x^2-13x^3+9x^4-3x^5+x^6). - R. J. Mathar, Jul 10 2008
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MATHEMATICA
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LinearRecurrence[{5, -11, 13, -9, 3, -1}, {0, 0, 0, 0, 0, 1}, 40] (* Harvey P. Dale, Sep 20 2012 *)
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CROSSREFS
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KEYWORD
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sign,easy
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AUTHOR
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EXTENSIONS
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STATUS
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approved
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