Numerical simulation of 25 double pendulums each consisting of a pendulum with another pendulum attached to its end, start moving with slightly different initial conditions: The outer masses of the double pendulums increase by 0.1 % from left to right, the inner masses by the same factor from front to back. In the beginning, the motion of both double pendulums is equal, but starts to differ after a certain time showing the chaotic behaviour of such chaos pendulums with a long-term dependency of the motion on the initial conditions. The double pendulums along the diagonal having the same ratio between both masses, however, show the exactly same motion.