OFFSET
1,2
EXAMPLE
sigma(196833) = 331968.
MATHEMATICA
lst = {}; Do[s = ToString@n; d = ToString@DivisorSigma[1, n]; If[StringLength@d == StringLength@d && {}!= StringPosition[s<>s, d], AppendTo[lst, n]], {n, 10^6}]; lst
CROSSREFS
KEYWORD
base,nonn,more
AUTHOR
Giovanni Resta, Jan 26 2006
STATUS
approved