Double Factorial: Introduction to the Alternate Factorial

Explore the concept of double factorial (!!), also known as alternate factorial, in this 16-minute video. Learn how this mathematical notation allows for skipping every other number while respecting the parity of its input. Examine examples of both standard and double factorials, and discover their applications in graph theory, particularly in solving problems related to perfect matchings. Gain insights into this unique mathematical operation and its practical uses in various mathematical contexts.