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A088546 Square root of sum of legs of primitive Pythagorean triangles having legs that add up to a square, sorted on hypotenuse.

%I A088546 #17 Mar 05 2020 04:56:09
%S A088546 7,17,23,31,47,41,49,71,73,79,89,97,113,103,119,119,127,137,151,161,
%T A088546 161,167,191,199,193,217,217,233,223,241,263,271,257,239,281,287,287,
%U A088546 313,289,329,329,343,311,353,367,337,359,383,409,391,401,391,433,439,463
%N A088546 Square root of sum of legs of primitive Pythagorean triangles having legs that add up to a square, sorted on hypotenuse.
%C A088546 Numbers whose square is the sum of the legs of primitive Pythagorean triangles with hypotenuse A088319(n).
%H A088546 Ray Chandler, <a href="/A088546/b088546.txt">Table of n, a(n) for n = 1..10000</a>
%F A088546 a(n) = abs(j^2 - k^2/2), where j=A088515(n), k=A088516(n).
%F A088546 a(n) = sqrt(A089552(n)).
%e A088546 31 is in the sequence because it is associated with the primitive Pythagorean triangle (400,561,689) where 400+561=31^2.
%t A088546 terms = 1000; jmax = 100; kmax = 200;
%t A088546 Reap[Do[If[CoprimeQ[j, k], e = j^2 - j k + k^2/2; f = j k; If[e > f, Sow[{e^2 + f^2, Abs[j^2 - k^2/2]}]]], {j, 1, jmax}, {k, 2, kmax, 2}]][[2, 1]] // Sort // #[[;; terms, 2]]& (* _Jean-François Alcover_, Mar 05 2020 *)
%Y A088546 Cf. A088319, A088515, A088516, A089545-A089552, A089554-A089558.
%K A088546 nonn
%O A088546 1,1
%A A088546 _Lekraj Beedassy_, Nov 17 2003
%E A088546 More terms from _Ray Chandler_, Nov 16 2003