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A278712 Triangle T read by rows: T(n, m), for n >= 2, and m = 1, 2, ..., n-1, equals the square root of the positive integer solution y of y^2 = x^3 - A(n, m)^2*x with the area A(n, m) = A249869(n, m) of the primitive Pythagorean triangle characterized by (n, m) or 0 if no such triangle exists. 1

%I #8 Nov 27 2016 22:02:55

%S 6,0,15,60,0,28,0,105,0,45,210,0,0,0,66,0,315,0,231,0,91,504,0,440,0,

%T 312,0,120,0,693,0,585,0,0,0,153,990,0,910,0,0,0,510,0,190,0,1287,0,

%U 1155,0,935,0,627,0,231,1716,0,0,0,1428,0,1140,0,0,0,276,0,2145,0,1989,0,1729,0,1365,0,897,0,325,2730,0,2618,0,2394,0,0,0,1610,0,1050,0,378,0,3315,0,3135,0,0,0,2415,0,0,0,0,0,435

%N Triangle T read by rows: T(n, m), for n >= 2, and m = 1, 2, ..., n-1, equals the square root of the positive integer solution y of y^2 = x^3 - A(n, m)^2*x with the area A(n, m) = A249869(n, m) of the primitive Pythagorean triangle characterized by (n, m) or 0 if no such triangle exists.

%C The corresponding solutions x are given in A278711, where also details are found.

%F T(n, m) = (n^2 - m^2)*n if n > m >= 1, gcd(n, m) = 1 and n+m is odd, and T(n, m) = 0 otherwise.

%e The triangle T(n, m) begins:

%e n\m 1 2 3 4 5 6 7 8 9 10

%e 2: 6

%e 3: 0 15

%e 4: 60 0 28

%e 5: 0 105 0 45

%e 6: 210 0 0 0 66

%e 7: 0 315 0 231 0 91

%e 8: 504 0 440 0 312 0 120

%e 9: 0 693 0 585 0 0 0 153

%e 10: 990 0 910 0 0 0 510 0 190

%e 11: 0 1287 0 1155 0 935 0 627 0 231

%e ...

%e n = 12: 1716 0 0 0 1428 0 1140 0 0 0 276,

%e n = 13: 0 2145 0 1989 0 1729 0 1365 0 897 0 325,

%e n = 14: 2730 0 2618 0 2394 0 0 0 1610 0 1050 0 378,

%e n = 15: 0 3315 0 3135 0 0 0 2415 0 0 0 0 0 435.

%e ...

%e For the solutions [x,y] see A278711.

%Y Cf. A278711.

%K nonn,tabl,easy

%O 2,1

%A _Wolfdieter Lang_, Nov 27 2016

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