%I #2 Mar 30 2012 17:26:35
%S 3,7,15,564210119465811
%N Odd terms in A007497.
%t n=2;Do[If[OddQ[n=DivisorSigma[1,n]],Print[n]],{k,2,99}]
%Y A007497, A175877.
%K more,nonn
%O 1,1
%A _Zak Seidov_, Oct 07 2010