[seqfan] Exactly two subsets of proper divisors of n sum to n.

[zak seidov]

Dear seqfans,

This is a draft of (possible) submission,
pending your YEAS AND NAYS...

%N 
Exactly two subsets of proper divisors of n sum to n.
%C 
Or numbers n such that A065205(n)=2.
There are exactly 327 such numbers <10^4:
12,18,42,...,,9928,9948,9966, all even.
%e 
n=12: proper divisors of 12 =  {1,2,3,4,6} and 12=2+4+6=1+2+3+6\Q
n=9966: proper divisors of 9966 =  {1,2,3,6,11,22,33,66,151,302,453,906,1661,3322,4983} and\Q
9966=1661+3322+4983=302+453+906+3322+4983.
%C 
Are there odd such numbers?
Any theory behind this?

%Y
Cf. A065205 Number of subsets of proper divisors of n that sum to n.\Q
A064771 Let S(n)=set of divisors of n,excluding n;
sequence gives n such that there is a unique subset of S(n) that sums to n.\Q
A065235 Odd numbers in A064771.

%E
Thanks ,
Zak