A112816 Numbers k such that lcm(1,2,3,...,k)/9 equals the denominator of the k-th harmonic number H(k).

63, 64, 65, 69, 70, 71, 189, 190, 191, 192, 193, 194, 195, 196, 197, 207, 208, 209, 210, 211, 212, 213, 214, 215, 1701, 1702, 1703, 1704, 1705, 1706, 1707, 1708, 1709, 1710, 1711, 1712, 1713, 1714, 1715, 1716, 1717, 1718, 1719, 1720, 1721, 1722, 1723, 1724

Offset

1,1

Comments

When 9 occurs in A110566.

Links

Amiram Eldar, Table of n, a(n) for n = 1..10000 (terms 1..1483 from Jinyuan Wang)

Mathematica

f[n_] := LCM @@ Range[n]/Denominator[ HarmonicNumber[n]]; Select[ Range[1724], f[ # ] == 9 &]

Crossrefs

Cf. A002805, A003418, A110566.

Cf. A098464, A112813, A112814, A112815, A112817, A112818, A112819, A112820, A112821, A112822.

Sequence in context: A365400 A365397 A332926 * A296875 A346803 A263282

Adjacent sequences: A112813 A112814 A112815 * A112817 A112818 A112819

Keyword

nonn

Author

Robert G. Wilson v, Sep 17 2005

Extensions

Definition corrected by Jinyuan Wang, May 03 2020

Status

approved