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A120212 "a" values providing solution x = b in A120211 (i.e., y^2 = b^2*(a^2 - b)*(b + 1) with a, b legs in primitive Pythagorean triangles).

%I A120212 #10 Nov 26 2015 00:19:17
%S A120212 3,5,7,8,9,11,13,17,19,21,23,25,27,29,31,33,35,37,39,41,43,45,47,49,
%T A120212 51,53,55,57,59,61,63,65,67,69,71,73,75
%N A120212 "a" values providing solution x = b in A120211 (i.e., y^2 = b^2*(a^2 - b)*(b + 1) with a, b legs in primitive Pythagorean triangles).
%D A120212 G. Balzarotti and P. P. Lava, Le sequenze di numeri interi, Hoepli, 2008, p. 47.
%e A120212 First primitive Pythagorean triad: 3, 4, 5.
%e A120212 Weierstrass equation: y^2 = x*(3^2 - x)*(4^2 + x).
%e A120212 Smallest integer solution: (x, y) = (4,20).
%e A120212 As x = b, the first element in the sequence is a = 3.
%K A120212 nonn
%O A120212 1,1
%A A120212 _Giorgio Balzarotti_, _Paolo P. Lava_, Jun 10 2006