OFFSET
0,1
REFERENCES
Richard K. Guy, Unsolved Problems in Number Theory, 3rd Edition, Springer, 2004, Section B6, pp. 92-95.
LINKS
Amiram Eldar, Table of n, a(n) for n = 0..1008 (from factordb.com; terms 0..268 from T. D. Noe)
Christophe Clavier, Aliquot Sequences.
factordb.com, Aliquot sequence of 660.
Paul Zimmermann, Latest information.
FORMULA
a(n+1) = A001065(a(n)). - R. J. Mathar, Oct 11 2017
MATHEMATICA
FixedPointList[If[# > 0, DivisorSigma[1, #] - #, 0]&, 660, 100] (* Jean-François Alcover, Mar 28 2020 *)
CROSSREFS
KEYWORD
nonn
AUTHOR
STATUS
approved