greedy computation of pseudoperfect numbers?

[Joshua Zucker]

On Mon, Apr 7, 2008 at 9:14 PM, Joerg Arndt <arndt at jjj.de> wrote:
> For both sorts of pseudoperfect numbers, allowing divisor one A005835,
>  and forbidding divisor one A136446, a greedy method _seems_ to always
>  work for deciding whther a given n in in the sequence:

I think if you scroll down at
  http://www.ics.uci.edu/~eppstein/numth/egypt/odd-one.html

you'll find that it only USUALLY works, not always.

>  Moreover, (disallowing the divisors one,) can any odd number n be in
>  sequence A136446?  This is of interest because all gcd computations in
>  a Rabin-like irreducibility test for polynomials over finite fields
>  (have to write it up) can be avoided for all numbers _not_ in A136446.

In the same source it looks like there's a conjecture that there is an
odd number in the sequence but that nobody had crunched enough numbers
to find it.

--Joshua Zucker