Search for right rectangles with edges of natural number length.

right_triangle_of_natural_numbers.py

def right_triangle_of_natural_numbers(max_n):
    '''
    Return all right traiangles whose edges are natural number length.
    Triangles of same ratio are discarded.

    >>> right_triangle_of_natural_numbers(5)
    [(5, 4, 3)]
    >>> right_triangle_of_natural_numbers(20)
    [(5, 4, 3), (13, 12, 5), (17, 15, 8)]    
    '''
    t = []
    for a in range(1,max_n + 1):
        for b in range(1, a):
            for c in range(1, b):
                if a*a==b*b+c*c:
                    for n in range(1, a):
                        if (a/n, b/n, c/n) in t: break
                    else:
                        t.append((a, b, c))
    return t