OFFSET
1,2
LINKS
Amiram Eldar, Table of n, a(n) for n = 1..10000
EXAMPLE
Number 36 is in sequence because sigma(36) = 91, sigma(37) = 38 and there are no other numbers m, n with sigma(m) = 91 or sigma(n) = 38.
CROSSREFS
KEYWORD
nonn
AUTHOR
Jaroslav Krizek, Apr 20 2012
STATUS
approved