tetration
English
Etymology
tetra- + (itera)tion; coined by Reuben Goodstein
Noun
Wikipedia tetration (uncountable)
- (arithmetic) The arithmetic operator consisting of repeated exponentiation, by analogy with exponentiation being repeated multiplication and multiplication being repeated addition, ba denoting a to the power of a to the power of ... to the power of a, in which a appears b times. Notation: ba,
or 
or 
Synonyms
- exponential map, hyper4, hyperpower, power tower, superexponentiation