Exact generalised harmonic numbers The generalised harmonic number of order \$m\$ of \$n\$ is
$$H_{n,m} = \sum_{k=1}^n \frac 1 {k^m}$$
For example, the harmonic numbers are \$H_{n,1}\$, and \$H_{\infty,2} = \frac {\pi^2} 6\$. These are related to the Riemann zeta function as
$$\zeta(m) = \lim_{n \to \infty} H_{n,m}$$
Given two positive integers \$n &gt; 0\$, \$m &gt; 0\$, output the exact rational number \$H_{n,m}\$. The fraction should be reduced to its simplest term (i.e. if it is \$\frac a b\$, \$\gcd(a, b) = 1\$). You may output as a numerator/denominator pair, a rational number or any clear value that distinguishes itself as a rational number. You may not output as a floating point number.
This is code-golf, so the shortest code in bytes wins
Test cases
n, m -&gt; Hₙ,ₘ
3, 7 -&gt; 282251/279936
6, 4 -&gt; 14011361/12960000
5, 5 -&gt; 806108207/777600000
4, 8 -&gt; 431733409/429981696
3, 1 -&gt; 11/6
8, 3 -&gt; 78708473/65856000
7, 2 -&gt; 266681/176400
6, 7 -&gt; 940908897061/933120000000
2, 8 -&gt; 257/256
5, 7 -&gt; 2822716691183/2799360000000
M, 4 bytes
Rİ*S

Try it online!
Obligatory trivial answer ;-;
Rİ*S  Main Link; takes n on the left and m on the right
R     Range: [1, 2, 3, ..., n]
 İ    Inverse/Reciprocal: [1, 1/2, 1/3, ..., 1/n]
  *   Exponent: [1, 1/2^m, 1/3^m, ..., 1/n^m]
   S  Sum