(aviation, travel) A callsign assigned to a commercial flight for the purposes of reservation and ticketing, typically consisting of a 2 character airline code and a 1 to 4 digit number to indicate a particular service.

A positive integer x, y or z that is part of a solution to the Markov Diophantine equation x²+y²+z²=3xyz.

plural of Markov number

(mathematics) The equivalent of a complex number in three dimensions

(number theory) Any of several extremely large numbers used as upper bounds for the smallest natural number x for which 𝜋(x)> operatorname li(x), where 𝜋 is the prime-counting function and li is the logarithmic integral function. These bounds have since been improved by others.

plural of Skewes' number

plural of covering number

plural of numerical noun

(library science) An alphanumeric code used for efficiently sorting names, etc. into alphabetical order.

plural of Cutter number