and 
where each summation runs over 
variables 
and 
Then find the value of 
lie on the same circle. If 
and 
,
,
or 11. However, I didn't know how to find the radius. Can anyone give me a hint?
and 
,![\[0<\frac{a-b}{1+ab} < \sqrt{2}-1.\]](http://latex.artofproblemsolving.com/1/3/f/13fde7ce3103520261558d05100032a735802cbc.png)
Y by Kizaruno
A positive even integer 
is called stylish if the set 
can be partitioned into 
pairs such that the sum of the elements in each pair is a power of 
. For example, 
is stylish because the set 
can be partitioned as 
, with sums , 
, and respectively. Determine the number of stylish numbers less than 
.
is called stylish if the set 
can be partitioned into 
pairs such that the sum of the elements in each pair is a power of 
. For example, 
is stylish because the set 
can be partitioned as 
, with sums , 
, and respectively. Determine the number of stylish numbers less than 
.This post has been edited 1 time. Last edited by pedronis, Apr 13, 2025, 5:40 PM
