The [$]\sqrt 7[$] identity is wrong. The continued fraction should be the golden ratio with the only radical being [$]\sqrt 5[$]. So the two side cannot be equal.

so he messed up that also?

well supposedly he forgot the ln in front of 2, so they had to add "ln" above the 2 later on, can be seen from the painting kind off. And now u say one more error, I need to tell them and ask if they can fix it. this is what happen when one hire painters/artists with no math skills?

or a math-smart painter putting in math errors on purpose? wanting people to think...?

What yer Norwegian artist (like Kevin Spacey) wanted to say was that every

*algebraic number *such as [$]\sqrt n[$] for each [$]n \in \mathbb{Z} [$] has a continued fraction expansion (but there was not enough space on the margin). So, can we close this discussion by saying that each algebraic number can be characterised by Cauchy sequence of continued fractions?