OFFSET
1,1
LINKS
Amiram Eldar, Table of n, a(n) for n = 1..1000
EXAMPLE
n=100: list={100, [30, 42, 54], 30, ... after 1 transient a 3-cycle arises.
MATHEMATICA
s[n_] := If[n > 1, Times @@ (1 + Power @@@ FactorInteger[n]) - n, 0]; useq[n_] := Most[NestWhileList[s, n, UnsameQ, All]]; cycleQ[k_] := Module[{s1 = s[k]}, s1 != k && s[s[s1]] == k]; aQ[n_] := cycleQ[Last[useq[n]]]; Select[Range[1000], aQ] (* Amiram Eldar, Apr 06 2019 *)
CROSSREFS
KEYWORD
nonn
AUTHOR
Labos Elemer, Aug 30 2004
STATUS
approved