%N Ordered set of c + a - b as (a,b,c) runs through all primitive Pythagorean triples with a<b<c.
%H Ray Chandler, <a href="/A020891/b020891.txt">Table of n, a(n) for n = 1..10000</a>
%F a(n) = 2*A020892(n).
%Y Cf. A020892.
%A _Clark Kimberling_
%E Extended and corrected by _David W. Wilson_
%E Offset corrected to 1 by _Ray Chandler_, Jan 23 2020