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A112287 a(n) = denominator of sum of reciprocals of the terms of the continued fraction for H(n) = sum{k=1 to n} 1/k. +0
7
1, 2, 5, 12, 24, 4, 5, 35, 420, 156, 300, 45, 15, 39, 15351, 72, 1848, 10675, 300, 2142, 36, 5460, 15, 1870, 90, 63, 2040, 120, 138600, 3960, 1750320, 1324895, 440, 3945480, 5220, 158340, 1680, 3341100, 498960, 48048, 1260, 69264, 1510, 1168200, 568260 (list; graph; listen)
OFFSET

1,2

LINKS

Eric Weisstein's World of Mathematics, Harmonic Number

Eric Weisstein's World of Mathematics, Continued Fraction

EXAMPLE

1 +1/2 +1/3 +1/4 +1/5 +1/6 = 49/20 = 2 + 1/(2 + 1/(4 + 1/2)).

So a(6) is 4, the denominator of 7/4 = 1/2 + 1/2 + 1/4 + 1/2.

MATHEMATICA

f[n_] := Plus @@ (1/# &) /@ ContinuedFraction[Sum[1/k, {k, n}]]; Table[Denominator[f[n]], {n, 45}] (*Chandler*)

CROSSREFS

m-th harmonic number H(m) = A001008(m)/A002805(m).

Cf. A055573, A058027, A100398, A110020, A112286.

Sequence in context: A115520 A116735 A096376 this_sequence A127787 A116733 A116721

Adjacent sequences: A112284 A112285 A112286 this_sequence A112288 A112289 A112290

KEYWORD

nonn,frac

AUTHOR

Leroy Quet (qq-quet(AT)mindspring.com), Sep 01 2005

EXTENSIONS

Extended by Hans Havermann and Ray Chandler (rayjchandler(AT)sbcglobal.net), Sep 06 2005

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Last modified August 29 17:54 EDT 2008. Contains 143238 sequences.


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