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Search: id:A136391
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| A136391 |
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a(n)=n*F(n) - (n-1)*F(n-1), where the F(j)'s are the Fibonacci numbers (F(0)=0, F(1)=1). |
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+0
1
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| 1, 1, 4, 6, 13, 23, 43, 77, 138, 244, 429, 749, 1301, 2249, 3872, 6642, 11357, 19363, 32927, 55861, 94566, 159776, 269469, 453721, 762793, 1280593, 2147068, 3595422, 6013933, 10048559
(list; graph; listen)
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OFFSET
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1,3
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FORMULA
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Equals A128064 * A000045
G.f.: x(1-x)(1+x^2)/(1-x-x^2)^2. a(n) = 2*a(n-1) +a(n-2) -2*a(n-3) -a(n-4) = A045925(n) -A045925(n-1). a(n) = A014286(n-1)-A014286(n-2), n>3. [From R. J. Mathar (mathar(AT)strw.leidenuniv.nl), Nov 25 2008]
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EXAMPLE
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a(6) = 23 = 6*F(6) - 5*F(5) = 6*8 - 5*5 = 48 - 25.
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MAPLE
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with(combinat): seq(n*fibonacci(n)-(n-1)*fibonacci(n-1), n=1..30); - Emeric Deutsch (deutsch(AT)duke.poly.edu), Jan 01 2008
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CROSSREFS
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Cf. A000045.
Adjacent sequences: A136388 A136389 A136390 this_sequence A136392 A136393 A136394
Sequence in context: A012964 A120463 A049732 this_sequence A105205 A012776 A016072
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KEYWORD
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nonn
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AUTHOR
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Gary W. Adamson (qntmpkt(AT)yahoo.com), Dec 28 2007
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EXTENSIONS
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More terms from Emeric Deutsch (deutsch(AT)duke.poly.edu), Jan 01 2008
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