%N Ordered set of (b + c - a)/2 as (a,b,c) runs through all primitive Pythagorean triples with a < b < c.
%C From _Bernard Schott_, May 06 2021: (Start)
%C Also, ordered sides b of primitive triples (a, b, c) for integer-sided triangles where side a is the harmonic mean of the 2 other sides b and c, i.e., 2/a = 1/b + 1/c with b < a < c (A343892).
%C The first term appearing twice is 330 = a(71) = a(72). (End)
%H Ray Chandler, <a href="/A020890/b020890.txt">Table of n, a(n) for n = 1..10000</a>
%F a(n) = A020889(n)/2.
%Y Cf. A020889.
%Y Cf. Triangles with 2/a = 1/b + 1/c: A343891 (triples), A020883 (side a), A343892 (side b), A343893 (side c), A343894 (perimeter).
%A _Clark Kimberling_
%E Offset corrected to 1 by _Ray Chandler_, Jan 23 2020