factorial series

factorial series

[fak¦tȯr·ē·əl ′sir‚ēz]
(mathematics)
The series 1 + (1/1!) + (1/2!) + (1/3!) + ⋯, whose (n + 1)st term is 1/ n ! for n = 1, 2, ⋯; its sum is the number e.