The hyperfactorial is the function defined by H(n) | congruent | K(n + 1) | = | product_(k = 1)^n k^k, where K(n) is the K-function. The hyperfactorial is implemented in the Wolfram Language as Hyperfactorial[n]. For integer values n = 1, 2, ... are 1, 4, 108, 27648, 86400000, 4031078400000, 3319766398771200000, ... (OEIS A002109). The hyperfactorial can also be generalized to complex numbers, as illustrated above.

Barnes G-function | Glaisher-Kinkelin constant | K-function | superfactorial