OFFSET
1,2
COMMENTS
Complement of A162923. - Jaroslav Krizek, Jul 19 2009
LINKS
Ivan Neretin, Table of n, a(n) for n = 1..10000
MATHEMATICA
mx = 400; Select[Union@Table[Nest[DivisorSigma[1, #] &, n, 2], {n, mx}], # < mx &] (* Ivan Neretin, Feb 12 2018 *)
CROSSREFS
KEYWORD
easy,nonn
AUTHOR
Benoit Cloitre, May 10 2002
STATUS
approved