In mathematics, the Fibonacci numbers form a sequence defined by the following recurrence relation:
That is, after two starting values, each number is the sum of the two preceding numbers. The first Fibonacci numbers (sequence A000045 in OEIS), also denoted as Fn, for n = 0, 1, … , are:
The Fibonacci numbers are named after Leonardo of Pisa, known as Fibonacci, although they had been described earlier in India.