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A127815
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a(n) = denominator of b(n), where b(1) = 2, b(n) = b(n-1) - 1/b(n-1).
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2
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1, 2, 6, 30, 330, 257070, 128005692870, 23279147893155496537470, 388475314992168993748220639081347493631827670, 102339769648127358726761918460732576814168548432921287355299929744910591862606847215978930
(list; graph; refs; listen; history; internal format)
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OFFSET
| 1,2
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FORMULA
| For n >=2, a(n) = a(n-1)*A127814(n-1).
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EXAMPLE
| The b() sequence is 2, 3/2, 5/6, -11/30, 779/330, 497941/257070, 181860254581/128005692870, ...
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MATHEMATICA
| f[l_List] := Append[l, l[[ -1]] - 1/l[[ -1]]]; Denominator[Nest[f, {2}, 10]] (*Chandler*)
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CROSSREFS
| Cf. A127814.
Sequence in context: A071350 A038696 A064847 * A054934 A001684 A076926
Adjacent sequences: A127812 A127813 A127814 * A127816 A127817 A127818
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KEYWORD
| easy,frac,nonn
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AUTHOR
| Leroy Quet Jan 30 2007
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EXTENSIONS
| Extended by Ray Chandler (rayjchandler(AT)sbcglobal.net), Feb 07 2007
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