OFFSET
1,2
COMMENTS
The prime tower factorization of a number is defined in A182318.
LINKS
Rémy Sigrist, Table of n, a(n) for n = 1..10000
Rémy Sigrist, Illustration of initial terms
FORMULA
a(n) <= n with equality iff n = 1 or n is a prime number.
a(n) = a(A053585(n)).
EXAMPLE
See Links section.
PROG
(PARI) a(n) = if (n==1, 1, my (f=factor(n), w=#f~); if (f[w, 2]==1, f[w, 1], a(f[w, 2])))
CROSSREFS
KEYWORD
nonn
AUTHOR
Rémy Sigrist, Apr 23 2021
STATUS
approved