1# 最后的例子用 Mathematica7 验证如下:- Table[a[i] = i^4, {i, 1, 10}];
- Table[a[i] = -a[i - 10], {i, 11, 20}];
- Table[a[i], {i, 1, 20}]
- A = Flatten[Table[a[i] + a[j], {i, 1, 20}, {j, i, 20}]];
- Length[A]
- Length[Union[A]]
- B = Flatten[Table[Abs[a[i] - a[j]], {i, 1, 19}, {j, i + 1, 20}]];
- Length[B]
- Length[Union[B]]
复制代码 输出
{1, 16, 81, 256, 625, 1296, 2401, 4096, 6561, 10000, -1, -16, -81, -256, -625, -1296, -2401, -4096, -6561, -10000}
210
201
190
100
后面的四个数分别就是1#证明过程提到的数值,这说明那列数是符合的。 |