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A112821 Numbers n such that LCM(1,2,3,...,n)/19 equals the denominator of the n-th harmonic number H(n). 9
343, 344, 345, 346, 347, 348, 349, 350, 351, 352, 353, 354, 355, 356, 357, 358, 359, 360 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

Positions where 19 occurs in A110566.

LINKS

Table of n, a(n) for n=1..18.

Tanya Khovanova, Non Recursions

MATHEMATICA

a = h = 1; t = {}; Do[a = LCM[a, n]; h = h + 1/n; If[a/Denominator[h] == 19, AppendTo[t, n]], {n, 10^6}]; t

Select[Range[500], Denominator[HarmonicNumber[#]]==LCM@@Range[#]/19&] (* Harvey P. Dale, Jan 29 2012 *)

CROSSREFS

Cf. A002805, A003418, A110566.

Cf. A098464, A112813, A112814, A112815, A112816, A112817, A112818, A112819, A112820, A112822.

Sequence in context: A035844 A028681 A005072 * A045130 A045269 A043395

Adjacent sequences:  A112818 A112819 A112820 * A112822 A112823 A112824

KEYWORD

nonn,more

AUTHOR

Robert G. Wilson v, Sep 17 2005

EXTENSIONS

Definition corrected by Max Alekseyev, Mar 03 2007

STATUS

approved

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Last modified September 26 10:46 EDT 2017. Contains 292518 sequences.