This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.
%I A278712 #8 Nov 27 2016 22:02:55 %S A278712 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 A278712 312,0,120,0,693,0,585,0,0,0,153,990,0,910,0,0,0,510,0,190,0,1287,0, %U A278712 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 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. %C A278712 The corresponding solutions x are given in A278711, where also details are found. %F A278712 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 A278712 The triangle T(n, m) begins: %e A278712 n\m 1 2 3 4 5 6 7 8 9 10 %e A278712 2: 6 %e A278712 3: 0 15 %e A278712 4: 60 0 28 %e A278712 5: 0 105 0 45 %e A278712 6: 210 0 0 0 66 %e A278712 7: 0 315 0 231 0 91 %e A278712 8: 504 0 440 0 312 0 120 %e A278712 9: 0 693 0 585 0 0 0 153 %e A278712 10: 990 0 910 0 0 0 510 0 190 %e A278712 11: 0 1287 0 1155 0 935 0 627 0 231 %e A278712 ... %e A278712 n = 12: 1716 0 0 0 1428 0 1140 0 0 0 276, %e A278712 n = 13: 0 2145 0 1989 0 1729 0 1365 0 897 0 325, %e A278712 n = 14: 2730 0 2618 0 2394 0 0 0 1610 0 1050 0 378, %e A278712 n = 15: 0 3315 0 3135 0 0 0 2415 0 0 0 0 0 435. %e A278712 ... %e A278712 For the solutions [x,y] see A278711. %Y A278712 Cf. A278711. %K A278712 nonn,tabl,easy %O A278712 2,1 %A A278712 _Wolfdieter Lang_, Nov 27 2016