Editing Function (mathematics) (section)

=== By recurrence ===
{{main|Recurrence relation}}
Functions whose domain are the nonnegative integers, known as [[sequence]]s, are sometimes defined by [[recurrence relation]]s.

The [[factorial]] function on the nonnegative integers (<math>n\mapsto n!</math>) is a basic example, as it can be defined by the recurrence relation

<math display="block">n!=n(n-1)!\quad\text{for}\quad n>0,</math>

and the initial condition

<math display="block">0!=1.</math>