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 ⅓+⅕=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...:-)