%I #21 Aug 03 2014 14:01:34
%S 3,14,15,168,326,5414,33357341,4324809536
%N Numbers n such that sigma(n) + tau(n) is a perfect number (A000396).
%C A002093(848) < a(9) <= 1155321467378283328. - Donovan Johnson, Nov 03 2011
%t perfect = {6, 28, 496, 8128, 33550336, 8589869056, 137438691328}; Select[Range[10000], MemberQ[perfect, DivisorSigma[0, #] + DivisorSigma[1, #]] &] (* _T. D. Noe_, Nov 03 2011 *)
%Y Cf. A007503 (sigma(n) + tau(n)).
%K nonn
%O 1,1
%A _Jeff Kruse_, Oct 26 2011
%E a(8) from _Donovan Johnson_, Nov 03 2011
|