OFFSET
0,1
COMMENTS
It is not known if this sequence reaches the value 1 and stops, or if it enters a cycle or diverges.
LINKS
Rémy Sigrist, Table of n, a(n) for n = 0..3998
EXAMPLE
a(0) = 397 is an odd prime, so a(1) = 397^2 - 1 = 157608.
a(1) = 157608 is even, so a(2) = a(1)/2 = 78804.
PROG
(PARI) v=397; for (n=1, 32, print1 (v", "); v=if (v%2==0, v/2, isprime(v), v^2-1, v-1))
CROSSREFS
KEYWORD
AUTHOR
Rémy Sigrist, Jan 07 2021
STATUS
approved