ABSTRACT
https://www.w3.org/1998/Math/MathML"> π 2 6 = 1 + 1 n + 1 n 2 + 1 n 3 + 1 n 4 ⋯ https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9781003339120/325239fb-e16b-4ec5-8024-2aee234eb0dd/content/eqn0006a.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/>
I discovered unexpectedly an elegant expression of the sum of the serie: I discovered that six times the sum is equal to the square of the length of the circle with diameter equal to 1.
Leonhard Euler, solution to the Bale problem (1741).
