Fibonacci numbers are generated by an algorithm which is easily converted into a computer program.

The first fibonacci numbers are:

0 1 1 2 3 5 8 13 21 34 55

The ninth number is 21, which is the sum of the two previous numbers, 8 + 13.

Likewise, 55 = 34 + 21.

By definition, the first two are 0, 1.

If you want to generate the 100'th fibonacci number, it's easy to say that it is the sum of the 99'th and the 98'th number, but what their value is, being tedious fast.

If you want to generate these numbers in a programming language (there is example fibonacci code for basically every language), you define a function (my example is in python, a programming language):

def fibonacci(n): # Returns the n'th fibonacci number

if n < 2:

return n # The zero'th fibonacci number is 0, the first one is 1, by definition.

else:

return fibonacci(n - 1) + fibonacci(n - 2)

This is quite similar to the explanation in English. If you can describe an algorithm in English (or in math), converting it into a computer-language is quite simple, although you'll have to learn the language first. Describing in English (or in math), what the algorithm does, with all the corner-cases, that's the hard part.