Arithmetic theory of harmonic numbers (II)

TL;DR

This paper derives new congruences involving harmonic numbers and Bernoulli numbers modulo primes, expanding the theoretical understanding of harmonic number properties in number theory.

Contribution

It establishes novel congruences for harmonic numbers and their generalizations modulo primes, providing new insights into their arithmetic properties.

Findings

Derived congruences involving harmonic numbers and Bernoulli numbers

Established relations for sums involving harmonic numbers modulo primes

Extended known results to more general harmonic number functions

Abstract

For $k=1,2,\ldots$ let $H_k$ denote the harmonic number $\sum_{j=1}^k 1/j$. In this paper we establish some new congruences involving harmonic numbers. For example, we show that for any prime $p>3$ we have $$\sum_{k=1}^{p-1}\frac{H_k}{k2^k}\equiv\frac7{24}pB_{p-3}\pmod{p^2},\ \ \sum_{k=1}^{p-1}\frac{H_{k,2}}{k2^k}\equiv-\frac 38B_{p-3}\pmod{p},$$ and $$\sum_{k=1}^{p-1}\frac{H_{k,2n}^2}{k^{2n}}\equiv\frac{\binom{6n+1}{2n-1}+n}{6n+1}pB_{p-1-6n}\pmod{p^2}$$ for any positive integer $n<(p-1)/6$, where $B_0,B_1,B_2,\ldots$ are Bernoulli numbers, and $H_{k,m}:=\sum_{j=1}^k 1/j^m$.