PROJECT EULER · #0737
Coin Loops
A game is played with many identical, round coins on a flat table.
Consider a line perpendicular to the table.
The first coin is placed on the table touching the line.
Then, one by one, the coins are placed horizontally on top of the previous coin and touching the line.
The complete stack of coins must be balanced after every placement.
The diagram below [not to scale] shows a possible placement of 8 coins where point

It is found that a minimum of
Also,
Calculate the number of coins needed to loop
Write-up coming later
The complete problem is available here. An approach, code, and answer will be added later.