Richard Dedekind was a renowned mathematician in the 19th century who made significant contributions to the field. He defined infinity rigorously and came up with the definition of real numbers that underpins modern mathematics. In one of his works, he explored a numerical pattern, which led to the discovery of what is now known as Dedekind numbers. These numbers count structures in various mathematical areas. Dedekind was unsure about the accuracy of his calculations, and later researchers confirmed his work. Recent computations by independent research groups determined the ninth Dedekind number, which consists of 42 digits. The growth of Dedekind numbers is so rapid that calculating them manually is impossible. Two papers published in April used different techniques to determine these numbers, emphasizing their vast and complex nature.
https://www.quantamagazine.org/ninth-dedekind-number-found-by-two-independent-groups-20230801/