OFFSET
1,1
COMMENTS
Analogous chains of length 3 (see A071869) are infinite as shown by Erdős and Pomerance (1978). What is true for longer successions of length=4,5,...?
LINKS
Donovan Johnson, Table of n, a(n) for n = 1..1000
P. Erdős and C. Pomerance, On the largest prime factors of n and n+1, Aequationes Math. 17 (1978), pp. 311-321. [alternate link]
EXAMPLE
n = 85293163: the corresponding uphill run of GPFs is (739, 5197, 6311, 7457, 8537, 1776941, 6561013, 8529317, 9477019, 21323293).
CROSSREFS
KEYWORD
nonn
AUTHOR
Labos Elemer, Dec 09 2004
STATUS
approved