This new formula is something else 😳
[…]

Ramanujan video: • Solving Mathematics in ‘The Man Who K…

Note, at 9:27, the n values should be minus 1 and the expression on the righthandside should be multiplied by 4. What I meant to write was:
n = 1: 4(1 – 1/3) ~= 2.66
n = 2: 4(1 – 1/3 + 1/5) ~= 3.42
n = 3: 4(1 – 1/3 + 1/5 – 1/7) ~= 2.89

[…]