Formulas July 22, 2020 General formula: !n=(n-1)[!(n-1)+!(n-2)]!0=1!1=0 Share Get link Facebook Twitter Pinterest Email Other Apps Share Get link Facebook Twitter Pinterest Email Other Apps
What is a "subfactorial"? Links! February 08, 2020 Wikipedia link Wolfram link (Other) subfactorial blog Online calculator Read more
Is there a relationship between n! and !n? April 17, 2023 Yes. Oh, you want more. Right, then: and (even cooler [if that's possible!]!) Read more