欧拉计划 发表于 2017-1-5 15:37:05

题目218:完美直角三角形

Perfect right-angled triangles

Consider the right angled triangle with sides a=7, b=24 and c=25. The area of this triangle is 84, which is divisible by the perfect numbers 6 and 28.
Moreover it is a primitive right angled triangle as gcd(a,b)=1 and gcd(b,c)=1.
Also c is a perfect square.

We will call a right angled triangle perfect if
-it is a primitive right angled triangle
-its hypotenuse is a perfect square

We will call a right angled triangle super-perfect if
-it is a perfect right angled triangle and
-its area is a multiple of the perfect numbers 6 and 28.

How many perfect right-angled triangles with c≤1016 exist that are not super-perfect?

题目:

一个边长分别为 a=7, b=24 和 c=25 的直角三角形,它的面积是 84,能被完全数 6 和 28 整除。另外,它还是原始直角三角形, 即满足 gcd(a,b)=1 和gcd(b,c)=1 。

并且,c 是完全平方数。



一个直角三角形如果满足以下条件,我们就称之为完美直角三角形:

-它是原始直角三角形

-它的斜边是完全平方数



一个超完美直角三角形需要满足以下条件:

-首先,它是个完美直角三角形,

-并且,它的面积是完全数 6 和 28 的倍数。



请问,在 c≤1016 (即斜边长小于等于 1016)范围内,存在多少个不是超完美直角三角形的完美直角三角形?

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