
1) Number theory
Found on
https://www.crosswordclues.com/clue/farey-sequence

In mathematics, the Farey sequence of order n is the sequence of completely reduced fractions between 0 and 1 which, when in lowest terms, have denominators less than or equal to n, arranged in order of increasing size. Each Farey sequence starts with the value 0, denoted by the fraction 0⁄1, and ends with the value 1, denoted by the fraction 1
Found on
http://en.wikipedia.org/wiki/Farey_sequence

A sequence of numbers named after the English geologist John Farey (1766 to 1826) who wrote about such sequences in an article called 'On a curious property of vulgar fractions' in the Philosophical Magazine in 1816. Farey says that he noted the 'curious property' while examining the tables of Compl...
Found on
http://www.daviddarling.info/encyclopedia/F/Farey_sequence.html
No exact match found.