(ˌsʌbfækˈtɔːrɪəl) n (Mathematics) maths the number of ways a group of objects can be arranged so that none of the objects are in their original or correct place
subfactorial
subfactorial
[‚səb‚fak′tȯr·ē·əl] (mathematics) For an integer n, the number that is expressed as n !{(½!) - (⅓!) + (¼!) - ⋯ + [(-1)n/ n !]}.