A112818 Numbers k such that lcm(1,2,3,...,k)/13 equals the denominator of the k-th harmonic number H(k).

156, 157, 158, 159, 160, 161, 27380, 27381, 27382, 27383, 27384, 27385, 27386, 27387, 27388, 27389, 27390, 27391, 27392, 27393, 27394, 27395, 27396, 27397, 27398, 27399, 27400, 27401, 27402, 27403, 27404, 27405, 27406, 27407, 27408

Offset

1,1

Comments

When 13 occurs in A110566.

Links

Jinyuan Wang, Table of n, a(n) for n = 1..851

Mathematica

a = h = 1; t = {}; Do[a = LCM[a, n]; h = h + 1/n; b = a/Denominator[h]; If[b == 13, AppendTo[t, n]], {n, 27408}]; t
With[{tk=Table[{LCM@@Range[k]/13, Denominator[HarmonicNumber[k]]}, {k, 28000}]}, Position[ tk, _?(#[[1]]==#[[2]]&), 1, Heads->False]]//Flatten (* Harvey P. Dale, Apr 02 2022 *)

Crossrefs

Cf. A002805, A003418, A110566.

Cf. A098464, A112813, A112814, A112815, A112816, A112817, A112819, A112820, A112821, A112822.

Sequence in context: A057966 A247435 A299170 * A047635 A295221 A052477

Adjacent sequences: A112815 A112816 A112817 * A112819 A112820 A112821

Keyword

nonn

Author

Robert G. Wilson v, Sep 17 2005

Extensions

Definition corrected by Jinyuan Wang, May 03 2020

Status

approved