A112821 Numbers n such that lcm(1,2,3,...,n)/19 equals the denominator of the n-th harmonic number H(n).

343, 344, 345, 346, 347, 348, 349, 350, 351, 352, 353, 354, 355, 356, 357, 358, 359, 360

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