%I A091290
%S A091290 1,4,7,10,13,22,31,37,46,49,52,58,61,67,73,82,85,94,97,106,112,115,121,
%T A091290 127,130,136,142,148,157,166,172,178,181,187,193,202,211,214,217,226,
%U A091290 229,232,238,241,247,253,256,262,274,277,283,292,298,301,307,310,313
%N A091290 Solutions x to (q=sigma[x]+sigma[x+1])/sigma[x+x+1], such that q<=1 i.e. 
               sigma[x]+sigma[x+1])<=sigma[2x+1];sigma[]=A000203.
%t A091290 Do[s=(DivisorSigma[1, n]+DivisorSigma[1, n+1])/ DivisorSigma[1, 2*n+1];
               If[ !Greater[s, 1], Print[n]], {n, 1, 10000000}]
%Y A091290 Cf. A000203, A091287-A091290.
%Y A091290 Sequence in context: A002640 A096675 A069212 this_sequence A119256 A143454 
               A065810
%Y A091290 Adjacent sequences: A091287 A091288 A091289 this_sequence A091291 A091292 
               A091293
%K A091290 nonn
%O A091290 1,2
%A A091290 Labos E. (labos(AT)ana.sote.hu), Feb 16 2004