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Mathematics

Mathematicians calculate 42-digit number after decades of trying

Dedekind numbers describe the number of ways sets of logical operations can be combined, and are fiendishly difficult to calculate, with only eight known since 1991 - and now mathematicians have calculated the ninth in the series

By Alex Wilkins

3 July 2023

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The ninth Dedekind number was calculated using the Noctua 2 supercomputer at Paderborn University in Germany

Paderborn University/Nils Winnwa

A 42-digit-long number that mathematicians have been hunting for decades, thanks to its sheer difficulty to calculate, has suddenly been found by two separate groups at the same time. This ninth Dedekind number, as it is known, may be the last in the sequence that is feasible to discover.

Dedekind numbers describe the number of ways a set of logical operations can be combined. For sets of just two or three elements, the total number…

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