The pentatri is equal to {3,3,3,3,3} or {3,5 (1) 2} (3 powergigoexploded to 3) in BEAF. or 5 & 3, using the array of operator. The term was coined by Jonathan Bowers. It is also quite close to the lower bound for \( G(16) \) in the Goodstein function, which illustrates that large numbers can appear in the modern mathematics. Chris Bird noted that Friedman's n(k) function is comparable to {3,k (1) 2}, so pentatri should be in ballpark with n(5).