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A120263 Ratio of the numerator of n*HarmonicNumber[n] to the numerator of HarmonicNumber[n]: A096617(n)/A001008(n). +0
1
1, 1, 1, 1, 1, 3, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 3, 1, 5, 3, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 11, 1, 1, 1, 1, 1, 1, 1, 1, 7, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 3, 1, 1, 1, 1, 1, 1, 1, 1, 3, 1, 1, 3, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 11, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 25, 1, 1, 1, 1 (list; graph; listen)
OFFSET

1,6

COMMENT

a(n) is not equal to 1 for n belongs to A074791 - numbers n such that n does not divide the denominator of the n-th harmonic number. a(n) is almost always equal to 1 except for n=6,18,20,21,33,42,54,.. when a(n) seems to be equal to a prime divisor of n. a(n) could be equal to a squared prime divisor of n as for n=100,294,500,847,..

FORMULA

a(n) = A096617(n)/A001008(n) = numerator[n*Sum[1/i,{i,1,n}]]/numerator[Sum[1/i,{i,1,n}]].

MATHEMATICA

Numerator[Table[n*Sum[1/i, {i, 1, n}], {n, 1, 500}]]/Numerator[Table[Sum[1/i, {i, 1, n}], {n, 1, 500}]]

CROSSREFS

Cf. A096617, A001008, A074791.

Sequence in context: A103755 A093818 A097031 this_sequence A030580 A030579 A030578

Adjacent sequences: A120260 A120261 A120262 this_sequence A120264 A120265 A120266

KEYWORD

frac,nonn

AUTHOR

Alexander Adamchuk (alex(AT)kolmogorov.com), Jun 26 2006

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Last modified December 20 16:40 EST 2009. Contains 171081 sequences.


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