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A120336
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Number of solutions (x,y) of Diophantine equation y^2 = x*(a^N - x)*(b^N + x) (Weierstrass elliptic equation) with a and b legs in primitive Pythagorean triangles and N = 2. Sequence ordered in increasing values of leg "a".
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0
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1, 1, 1, 1, 2, 1, 1, 1, 1, 1, 1, 2, 1, 1, 1, 1, 1, 2, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 3, 1, 1, 1, 1, 1, 1, 2, 1, 2, 1, 1, 1, 3, 1, 1, 1, 2, 1, 1, 1, 1, 1, 1, 1, 1, 2, 1, 1, 1, 2, 1, 1, 2, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 2, 1, 1, 1
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OFFSET
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1,5
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COMMENTS
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Triads a = 3, b = 4, c = 5 and a = 4, b = 3, c = 5 provide different results for (x,y).
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LINKS
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EXAMPLE
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First primitive Pythagorean triad: 3, 4, 5.
Weierstrass equation: y^2 = x*(3^2 - x)*(4^2 + x).
Unique integer solution: (x,y) = (4,20).
First element in the sequence: 1.
Fifth primitive Pythagorean triad: 8, 15, 17.
Integer solutions: (x,y) = (15, 420) and (30, 510).
Fifth element in the sequence: 2.
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MAPLE
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# a, b, c primitive Pythagorean triad n_sol:=0; for x from 1 by 1 to a^2 do y2:= x*( a^2 - x)*( x+ b^2); if ((floor(sqrt(y2)))^2=y2) n_sol:=n_sol+1; fi; print(n_sol) ; od;
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CROSSREFS
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KEYWORD
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nonn
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AUTHOR
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STATUS
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approved
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