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Search: id:A066356
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| A066356 |
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Numerator of sequence defined by recursion c(n)=1+c(n-2)/c(n-1), c(0)=0, c(1)=1. |
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+0
2
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| 0, 1, 1, 2, 3, 7, 23, 167, 3925, 661271, 2609039723, 1728952269242533, 4516579101127820242349159, 7812958861560974806259705508894834509747, 35298563436210937269618773778802420542715366288238091341051372773
(list; graph; listen)
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OFFSET
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0,4
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COMMENT
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a(i) and a(j) are relative prime for all i>j>0.
An infinite coprime sequence defined by recursion.
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FORMULA
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a(n) = (2*a(n - 1)*a(n - 2)^2 - a(n - 1)^2*a(n - 4) - a(n - 2)^3*a(n - 3))/(a(n - 2) - a(n - 3)*a(n - 4)).
a(n)=b(n)+b(n-1)*a(n-2) where b(n)=A064184(n).
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PROGRAM
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(PARI) a(n)=if(n<4, max(0, n)-(n>1), (2*a(n-1)*a(n-2)^2-a(n-1)^2*a(n-4)-a(n-2)^3*a(n-3))/(a(n-2)-a(n-3)*a(n-4)))
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CROSSREFS
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Cf. A001685, A002715, A003686, A006695, A064526.
Sequence in context: A001064 A108176 A111235 this_sequence A006892 A102710 A048824
Adjacent sequences: A066353 A066354 A066355 this_sequence A066357 A066358 A066359
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KEYWORD
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nonn,easy
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AUTHOR
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Michael Somos
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