OFFSET
0,3
LINKS
Matthew Campbell, Table of n, a(n) for n = 0..27
FORMULA
EXAMPLE
Hyperfactorial(Hyperfactorial(1)) = 1. There is 1 digit in the number 1. Because of this, a(1) = 1.
MATHEMATICA
Table[Floor[Log[10, Hyperfactorial[Hyperfactorial[n]]]] + 1, {n, 0, 3}]
PROG
(PARI) hyperfactorial(n)=prod(k=2, n, k^k)
first(m)=vector(m, i, #digits(hyperfactorial(hyperfactorial(i)))) \\ Anders Hellström, Aug 29 2015
CROSSREFS
KEYWORD
nonn,easy,base
AUTHOR
Matthew Campbell, Jul 21 2015
STATUS
approved