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A191864
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a(n) = (a(n-1) + a(n-4)) * (a(n-2) - a(n-3)) with a(1)=1, a(2)=2, a(3)=3 and a(4)=4
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0
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1, 2, 3, 4, 5, 7, 10, 28, 99, 1908, 136178, 246396654, 33083692025310, 8147205746460109635768, 269537638338486762080764802762484576, 2195978587041305889551144566841383797948181151148527903340
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OFFSET
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1,2
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LINKS
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Table of n, a(n) for n=1..16.
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FORMULA
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a(n) = (a(n-1) + a(n-4)) * (a(n-2) - a(n-3)) with a(1)=1, a(2)=2, a(3)=3 and a(4)=4
a(n) = k^(phi^n + o(1)) with k = 1.06164666362... and phi = (1+sqrt(5))/2. [Charles R Greathouse IV, Jun 21 2011]
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EXAMPLE
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a(5) = (4+1)*(3-2) = 5 ; a(6) = (5+2)*(4-3) = 7
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PROG
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(PARI) a=vector(20, i, i); for(n=6, #a, a[n]=(a[n-1]+a[n-4])*(a[n-2]-a[n-3])); a \\ Charles R Greathouse IV, Jun 21 2011
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CROSSREFS
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Sequence in context: A212463 A130080 A057496 * A180348 A001729 A001087
Adjacent sequences: A191861 A191862 A191863 * A191865 A191866 A191867
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KEYWORD
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nonn,changed
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AUTHOR
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Karsten Meyer, Jun 18 2011
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STATUS
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approved
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