If the first three Fibonacci numbers are given as x1 = 1, x2 = 1 and x3 = 2, then what is the least value of n for which xn 5,000?

Fibonacci numbers are a sequence of whole numbers
The rule for the Fibonacci numbers is given as :
The first number in the Fibonacci sequence is given as x_{0}=0
The second number in the Fibonacci sequence is given as x_{1}=1
The third number in the Fibonacci sequence is x{3} = x_{2} + x_{1}
The rule for Fibonacci numbers, if explained in simple terms, says that every number in the sequence is the sum of two numbers preceding it in the sequence.
Fibonacci numbers are a sequence of whole numbers arranged as follows:
So
x_{17} = x_{15}+ x_{16} = 610 + 987 = 1,597
x_{18} = x_{16} + x_{17} = 987 + 1,597 = 2,584
x_{19} =x_{17}+x_{18} = 1,597 + 2,584 = 4,181
x_{20} = x_{18} + x_{19} = 2,584 + 4,181 = 6,765
Therefore the least value of n for which xn > 5,000 is n = 20.
I found an answer from en.wikipedia.org
Fibonacci number - Wikipedia
In mathematics, the Fibonacci numbers, commonly denoted Fn, form a sequence, called the ... Fibonacci numbers are strongly related to the golden ratio: Binet's formula expresses the nth Fibonacci number in ... arguments using the fact that F n can be interpreted as the number of sequences of 1s and 2s that sum to n − 1.
For more information, see Fibonacci number - Wikipedia