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A128534
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F(n)*L(n-1) where F=Fibonacci and L=Lucas numbers.
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2
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0, 2, 1, 6, 12, 35, 88, 234, 609, 1598, 4180, 10947, 28656, 75026, 196417, 514230, 1346268, 3524579, 9227464, 24157818, 63245985
(list; graph; refs; listen; history; internal format)
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OFFSET
| 0,2
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COMMENTS
| Generally, F(n)*L(n+k) = F(2*n + k) + F(k)*(-1)^(n+1). If k=0 the sequence is A001906; if k=1 it is A081714.
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FORMULA
| a(n) = F(2*n - 1) + (-1)^(n+1), assuming F(0)=0 and L(0)=2.
a(n)=2*a(n-1)+2*a(n-2)-a(n-3). G.f.: -x*(-2+3*x)/((1+x)*(x^2-3*x+1)). [From R. J. Mathar (mathar(AT)strw.leidenuniv.nl), Apr 16 2009]
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EXAMPLE
| a(5) = 35 because F(5)*L(4) = 5*7
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CROSSREFS
| Cf. A001906, A081714, A128533, A128535.
Sequence in context: A113025 A113216 A081064 * A002562 A136456 A123968
Adjacent sequences: A128531 A128532 A128533 * A128535 A128536 A128537
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KEYWORD
| easy,nonn
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AUTHOR
| Axel Harvey (ax(AT)hirsig.ca), Mar 08 2007
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