Superfactorial 4$=4!3!2!1!

Sign up for a free account at https://brilliant.org/blackpenredpen/ and starting learning today . You can also get a 20% off discount for their annual premium subscription. Support this channel and get more content 👉   / blackpenredpen   Hyperfactorial,    • Hyperfactorial introduction   Note: on Wikipedia, it uses sf(n) for the Sloane and plouffe’s definition of the super factorial. But here it uses n$ for both http://mathworld.wolfram.com/Superfac...