The Fibonacci Sequence

fibonacci.js

/** 
 * 0, 1, 1, 2, 3, 5, 8, 13, 21, 34, ...
 * The next number is found by adding up the two numbers before it.
 *   - The 2 is found by adding the two numbers before it (1+1)
 *   - Similarly, the 3 is found by adding the two numbers before it (1+2),
 *   - And the 5 is (2+3), and so on
 */

// Using recursion
function fibonacciNumberOf(number) {
    return (
        number < 2 ? 
        number : 
        fibonacciNumberOf(number - 1) + fibonacciNumberOf(number - 2)
    );
}

console.log(fibonacciNumberOf(7));