OFFSET
155,2
COMMENTS
The same as 2^512. In this capacity, a floating point approximation is often casually given in computer programming textbooks (like the Hunt & Thomas) as an example where overflow is risked, and that risk is at times overcome, at others incurred.
3^3^3 = 7625597484987 (see A002488) while 5^5^5 is approximately 1.9110125979457752 * 10^2184.
REFERENCES
Andrew Hunt & David Thomas, The Pragmatic Programmer: From Journeyman to Master. New York: Addison-Wesley Longman (2000): 195, the fourth new element added to the object testData in the source code listing.
LINKS
T. D. Noe, Table of n, a(n) for n = 155..309 (complete sequence)
EXAMPLE
4^4^4 = 1.3407807929942597... * 10^154
MATHEMATICA
IntegerDigits[4^4^4]
PROG
(PARI) 4^4^4 \\ Charles R Greathouse IV, Aug 21 2015
CROSSREFS
KEYWORD
AUTHOR
Alonso del Arte, Jul 01 2012
STATUS
approved