Take two numbers with a difference of two

Take two numbers with a difference of two. Add the reciprocals. The numerator and the denominator of the result are the two short sides of a pythagorean triple. Eg &8531;+&8533;=8/15 82+152=172

Klopt...:-)

In stapjes:

$
\eqalign{
  & \frac{1}
{a} + \frac{1}
{{a + 2}} = \frac{{2a + 2}}
{{a(a + 2)}}  \cr
  & (2a + 2)^2  + (a(a + 2))^2  = (a^2  + 2a + 2)^2  \cr}
$

Leuk hoor...:-)