Named in memory of Leonardo Fibonacci of Pisa (c. 1170–1240), the first “western” mathematician, whose Liber abaci (1202) contains the earliest mention of the famous sequence of numbers that bears his name. The number of this minor planet is the twentieth in that sequence, the first five members of which are 1, 1, 2, 3 and 5, and every fifth member of which is divisible by five. (M 26767) _ _.