OFFSET
1,1
COMMENTS
Shiu (2016) proved that this sequence is infinite. Wu and Chen (2019) proved that the asymptotic density of this sequence is 1. - Amiram Eldar, Jan 29 2021
LINKS
Amiram Eldar, Table of n, a(n) for n = 1..10000
Peter Shiu, The denominators of harmonic numbers, arXiv:1607.02863 [math.NT], 2016.
Bing-Ling Wu and Yong-Gao Chen, On the denominators of harmonic numbers, II, Journal of Number Theory, Vol. 200 (2019), pp. 397-406.
EXAMPLE
For example: H(11) = 83711/27720, H(12) = 86021/27720 and so a(2) = 11.
MATHEMATICA
Position[Partition[Denominator @ HarmonicNumber[Range[126]], 2, 1], {x_, x_}] // Flatten (* Amiram Eldar, Jan 29 2021 *)
CROSSREFS
KEYWORD
nonn
AUTHOR
Benoit Cloitre, Nov 24 2001
STATUS
approved