Trienn

A trienn (also called triennet by Aarex Tiaokhiao) is equal to \(\{9,9,9\}\) or \(9\{9\}9\) in BEAF or 9 undecated to 9. This is the ninth Ackermann number.
==Etymology==
The name of this number is based on Greek prefixes tri- (three) and ennea- (nine), meaning that there are 3 9's in the array.
== Sources ==
== See also ==
Category:Numbers
Category:Numbers by Aarex Tiaokhiao
Category:Up-arrow notation level
Category:3 entry linear
Category:Greek-based name
Category:BEAF
Category:Powers of 3