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Ordered set of c + a - b as (a,b,c) runs through all primitive Pythagorean triples with a<b<c.
2

%I #13 Jan 24 2025 11:56:03

%S 4,6,8,10,10,12,14,14,16,18,18,20,22,22,24,26,26,28,28,30,30,32,34,34,

%T 36,36,38,38,40,42,42,42,44,44,46,46,48,48,50,50,52,52,54,54,56,58,58,

%U 60,60,60,62,62,64,66,66,66,66,68,68,70,70,72,74,74,76,76,78,78,78,78,80,82,82

%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).

%t pyth[nn_]:=Module[{tr={}}, Do[If[CoprimeQ[m,n]&&Mod[m+n,2]==1,AppendTo[tr,{m^2-n^2,2 m n,m^2+n^2}] ], {m,2,nn},{n,1,m-1}];tr]; Take[#[[3]]+#[[1]]-#[[2]]&/@(Sort/@pyth[50])//Sort,80] (* _Harvey P. Dale_, Jan 24 2025 *)

%Y Cf. A020892.

%K nonn,changed

%O 1,1

%A _Clark Kimberling_

%E Extended and corrected by _David W. Wilson_

%E Offset corrected to 1 by _Ray Chandler_, Jan 23 2020