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%I #5 Aug 29 2012 12:43:56
%S 3,9,15,21,27,39,57,63,81,93,105,117,165,171,183,189,201,219,225,243,
%T 256,279,303,309,333,351,363,375,381,387,405,417,441,453,471,489,512,
%U 543,549,567,579,603,633,651,657,669,687,693,723,729,741,777
%N Conjectured values of n such that sigma(n)+sigma(k)=sigma(n+k) has no solution.
%C All k<10^10 have been checked. Note that this sequence appears to contain all powers of 3. It also contains 256 and 512, which are the only even numbers listed here.
%C All k<10^11 have been checked. 65 n values remain < 1000. - _Donovan Johnson_, Aug 29 2012
%D R. K. Guy, Unsolved Problems in Number Theory, 3rd Ed., New York, Springer-Verlag, 2004, Section B15.
%Y Cf. A066435 (least k such that sigma(n)+sigma(k)=sigma(n+k)).
%K nonn
%O 1,1
%A _T. D. Noe_, Jul 12 2005
%E Two terms removed (465 and 711) by _Donovan Johnson_, Aug 29 2012
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