Use the following "Yoshisuke Matsunaga's formula" to find the approximate value of pi.
π= 3{1 + (1^2)/(4･6) + (1^2 ･ 3^2)/(4･6･8･10) + (1^2 ･ 3^2 ･ 5^2)/(4･6･8･10･12･14) + ･･･ }
Let's observe how the approximate value of pi can be obtained as the number of terms increases.
You can see that the convergence is very fast.