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A146882
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5*(4^(n+1)-1)/3.
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2
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5, 25, 105, 425, 1705, 6825, 27305, 109225, 436905, 1747625, 6990505, 27962025, 111848105, 447392425, 1789569705, 7158278825, 28633115305, 114532461225, 458129844905, 1832519379625, 7330077518505, 29320310074025
(list; graph; refs; listen; history; internal format)
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OFFSET
| 0,1
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LINKS
| Vincenzo Librandi, Table of n, a(n) for n = 0..1000
Index to sequences with linear recurrences with constant coefficients, signature (5,-4)
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FORMULA
| a(n) = 5*A002450(n+1).
G.f. 5 / ( (4*x-1)*(x-1) ). - R. J. Mathar, Jun 26 2011
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MATHEMATICA
| Clear[a, n]; a[n_] = Sum[5*4^m, {m, 0, n}]; Table[a[n], {n, 0, 30}]
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PROG
| (MAGMA) [5*(4^(n+1)-1)/3: n in [0..35]]; // Vincenzo Librandi, Jul 15 2011
(PARI) a(n)=20<<(2*n)\/3-2 \\ Charles R Greathouse IV, Jul 15 2011
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CROSSREFS
| Cf. A100774
Sequence in context: A022729 A098111 A083877 * A067971 A111641 A074419
Adjacent sequences: A146879 A146880 A146881 * A146883 A146884 A146885
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KEYWORD
| nonn,easy
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AUTHOR
| Roger L. Bagula (rlbagulatftn(AT)yahoo.com), Nov 02 2008
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