OFFSET
0,1
COMMENTS
a(10) = 4057230930. - Giovanni Resta, Aug 23 2017
FORMULA
EXAMPLE
a(5) = 1722 because sigma(1722) - 1722 = 2*3*5*7*11 = A002110(5) and 1722 is the least number with this property.
CROSSREFS
KEYWORD
nonn,hard,more
AUTHOR
Altug Alkan, Aug 23 2017
EXTENSIONS
a(7) confirmed by Giovanni Resta, Aug 23 2017
STATUS
approved