Editing Harmonic number (section)

===Hyperharmonic numbers===

The next generalization was discussed by [[John Horton Conway|J. H. Conway]] and [[Richard K. Guy|R. K. Guy]] in their 1995 book ''[[The Book of Numbers (maths)|The Book of Numbers]]''.<ref name=ConwayGuy/>{{rp|258}} Let
<math display="block"> H_n^{(0)} = \frac1n. </math>
Then the nth [[hyperharmonic number]] of order ''r'' (''r>0'') is defined recursively as
<math display="block"> H_n^{(r)} = \sum_{k=1}^n H_k^{(r-1)}. </math>
In particular, <math>H_n^{(1)}</math> is the ordinary harmonic number <math>H_n</math>.