The story
Named after Basel, the home town of Euler and of the Bernoulli family who unsuccessfully attacked the problem.
Etymology from Wiktionary, CC BY-SA 4.0.
Basel problem
Today it means: The question as to the value of ∑ₙ₌₁ ᪲1/(n²), the sum of the reciprocals of the squares of the positive integers. Full definition →