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A324220
Number of digits in n^(n^(n^n)).
2
1, 1, 1, 5, 3638334640025
OFFSET
-1,4
COMMENTS
Exponentiation is a right-associative operation: the power tower could be also written as n^n^n^n.
Here we set 0^0=1 by convention.
LINKS
Natan Arie' Consigli, Table of n, a(n) for n = -1..4
EXAMPLE
-1^-1^-1^-1 = -1 has one digit so a(-1)=1.
2^2^2^2 = 65536 has 5 digits so a(2)=5.
CROSSREFS
Cf. A244059 (initial digit), A054382 (number of digits in n^n^n).
Sequence in context: A094467 A242828 A177164 * A273941 A067483 A186685
KEYWORD
nonn,base
AUTHOR
Natan Arie Consigli, Feb 18 2019
STATUS
approved