maths.special_numbers.polygonal_numbers
=======================================

.. py:module:: maths.special_numbers.polygonal_numbers


Functions
---------

.. autoapisummary::

   maths.special_numbers.polygonal_numbers.polygonal_num


Module Contents
---------------

.. py:function:: polygonal_num(num: int, sides: int) -> int

   Returns the `num`th `sides`-gonal number. It is assumed that `num` >= 0 and
   `sides` >= 3 (see for reference https://en.wikipedia.org/wiki/Polygonal_number).

   >>> polygonal_num(0, 3)
   0
   >>> polygonal_num(3, 3)
   6
   >>> polygonal_num(5, 4)
   25
   >>> polygonal_num(2, 5)
   5
   >>> polygonal_num(-1, 0)
   Traceback (most recent call last):
       ...
   ValueError: Invalid input: num must be >= 0 and sides must be >= 3.
   >>> polygonal_num(0, 2)
   Traceback (most recent call last):
       ...
   ValueError: Invalid input: num must be >= 0 and sides must be >= 3.