TAOCP 1.2.7 Exercise 1
By definition, H_n = \sum_{k=1}^{n}\frac1k.
Section 1.2.7: Harmonic Numbers
Exercise 1. [01] What are $H_0$, $H_1$, and $H_2$?
Verified: no
Solve time: -
By definition,
$$ H_n = \sum_{k=1}^{n}\frac1k. $$
The empty sum gives
$$ H_0 = 0. $$
Furthermore,
$$ H_1 = 1, \qquad H_2 = 1+\frac12 = \frac32. $$
Therefore,
$$ \boxed{H_0=0,\quad H_1=1,\quad H_2=\frac32.} $$