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A112685
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a(n)=5a(n-2)+2a(n-3).
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1
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1, 1, 1, 7, 7, 37, 49, 199, 319, 1093, 1993, 6103, 12151, 34501, 72961, 196807, 433807, 1129957, 2562649, 6517399, 15073159, 37712293, 88400593, 218707783, 517427551, 1270340101, 3024553321, 7386555607, 17663446807, 42981884677, 103090345249
(list; graph; refs; listen; history; internal format)
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OFFSET
| 0,4
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COMMENTS
| Last digit has period 12.
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LINKS
| Index to sequences with linear recurrences with constant coefficients, signature (0,5,2).
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FORMULA
| Differences: 0, 0, 6, 0, 30, 12, 150, 120, 774 ... = 6*A135138.
O.g.f.: (-1-x+4*x^2)/((2*x+1)(x^2+2*x-1)) . a(n) = [(-2)^(n+1)+9*A000129(n+1)-15*A000129(n)]/7. - R. J. Mathar (mathar(AT)strw.leidenuniv.nl), Mar 17 2008
a(n)=(9/14)*[(1+sqrt(2))^n+(1-sqrt(2))^n]+(3/14)*sqrt(2)*[(1-sqrt(2))^n-(1+sqrt(2))^n]-(2/7)*(-2)^n, with n>=0 [From Paolo P. Lava (paoloplava(AT)gmail.com), Apr 23 2010]
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CROSSREFS
| Sequence in context: A095343 A121210 A154702 * A201958 A153721 A151791
Adjacent sequences: A112682 A112683 A112684 * A112686 A112687 A112688
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KEYWORD
| nonn
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AUTHOR
| Paul Curtz (bpcrtz(AT)free.fr), Mar 02 2008
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EXTENSIONS
| More terms from R. J. Mathar (mathar(AT)strw.leidenuniv.nl), Mar 17 2008
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