Ackermann Function is an extreme example of Recurrence Relations and
Recursive Functions.
The Ackermann function was discovered and studied by Wilhelm Ackermann (1896–1962) in 1928. Ackermann worked as a high-school teacher from 1927 to 1961 but was also a student of the great mathematician David Hilbert in Göttingen and, from 1953, served as an honorary professor in the university there. Together with Hilbert he published the first modern textbook on mathematical logic.
The Ackermann function can be defined as follows:
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