Concatenated anti-divisors

[Maximilian Hasler]

It appears to me that the definition

%C A066272 If an odd number d in the range 1 < d < n divides N where N
is any one of 2n-1, 2n or 2n+1 then N/d is called an anti-divisor of
n.

is not equivalent to your definition:

> Non-divisor: a number k which does not divide a given
> number x. Anti-divisor: a non-divisor k of x with the
> property that k is an odd divisor of 2x-1 or 2x+1, or
> an even divisor of 2x.

According to the first definition, n=3 cannot have an anti-divisor
since there is no odd d, 1<d<n.

M.H.