Super-exponentiation
Super-exponentiation (also tetration or power-tower) is iterated exponentiation. It is often written using Knuth's up-arrow notation, hyper operators, Conway chained arrow, or as (a@b).Using this final notation, we can create a recursive/inductive definition of super-exponentiation as a raised to the power a@(b-1), where a@1 is a.
Then the operation @ follows exponentiation in the sequence
- addition a+b,
- multiplication a×b,
- exponentiation ''ab,
- Then, a@b:
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The source of this notation is http://mathforum.org/library/drmath/view/54586.html.
1@2 = 1
2@2 = 4
3@2 = 27
4@2 = 256
5@2 = 3125
6@2 = 46,656
7@2 = 823,543
8@2 = 16,777,216
9@2 = 387,420,489
10@2 = 10,000,000,000
11@2 = 285,311,670,611
12@2 = 8,916,100,448,256
13@2 = 302,875,106,592,253
1@3 = 1
2@3 = 16
3@3 = 7,625,597,484,987
1@4 = 1
2@4 = 65,536
2@5 = A number with nearly 20,000 digits
1@n = 1 for all non-negative integers
n@1 = n for all real numbers
n@0 = 1 for all real numbers
n@(-1) = 0 for all real numbers not equal to 1
n@(-2) = negative infinity for all real numbers greater than 1
n@(-2) = infinity for all real numbers between 0 and 1Source
Some values