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Search: id:A084707
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| A084707 |
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a(0) = 1, a(1) = 3, a(2) = 9, a(3) = 27; a(n) = 3 a(n-1) - 3 a(n-3) + a(n-4). |
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2
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| 1, 3, 9, 27, 73, 195, 513, 1347, 3529, 9243, 24201, 63363, 165889, 434307, 1137033, 2976795, 7793353, 20403267, 53416449, 139846083, 366121801, 958519323, 2509436169, 6569789187, 17199931393, 45030004995, 117890083593
(list; graph; listen)
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OFFSET
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0,2
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LINKS
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J. Hietarinta and C.-M. Viallet, Singularity confinement and chaos in discrete systems, Physical Review Letters 81 (1998), pp. 326-328.
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FORMULA
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a(n)=-2+(8/5)*[3/2+(1/2)*sqrt(5)]^n-(1/5)*(-1)^n+(8/5)*[3/2-(1/2)*sqrt(5)]^n, with n>=0 [From Paolo P. Lava (ppl(AT)spl.at), Aug 01 2008]
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MATHEMATICA
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a[n_] := a[n] = 3 a[n - 1] - 3 a[n - 3] + a[n - 4]; a[0] = 1; a[1] = 3; a[2] = 9; a[3] = 27; Table[ a[n], {n, 0, 27}]
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CROSSREFS
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Cf. A069403.
Adjacent sequences: A084704 A084705 A084706 this_sequence A084708 A084709 A084710
Sequence in context: A103828 A110740 A042938 this_sequence A048481 A027027 A140348
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KEYWORD
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nonn,easy
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AUTHOR
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njas, Jul 06 2003
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EXTENSIONS
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More terms from Ray Chandler (rayjchandler(AT)sbcglobal.net), Jul 07 2003
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