OFFSET
1,2
LINKS
Amiram Eldar, Table of n, a(n) for n = 1..10000
EXAMPLE
Number 36 is in the sequence because sigma(36) = 91 and there is no other number m with sigma(m) = 91.
Number 6 is not in the sequence because sigma(6) = 12 and 12 is also sigma(11).
CROSSREFS
KEYWORD
nonn
AUTHOR
Jaroslav Krizek, Apr 20 2012
STATUS
approved