Evil numbers

[franktaw at netscape.net]

Sequence A001969 (the "evil" numbers, those with an even number of 1's
in their binary representation) has a comment: "Gelfond conjectured 
that
this sequence has asymptotic density 1/2."  I'm sure Gelfond was smart
enough to notice that 2n+1 is in the sequence iff 2n is not; and to 
realize
that any sequence which contains exactly 1 of 2n and 2n+1 has 
asymptotic
density 1/2.

So what should this comment really be?  Did Gelfond make his conjecture
about some similar sequence?  Did he arrive at this sequence in some 
very
different way, so that it wasn't clearly this sequence?  Or did he 
actually
prove it - or just state it as obvious - and somebody misread it as a
conjecture?

Franklin T. Adams-Watters