Returns the value of the Nth value of the fibonnacci sequence.

fibonnacci.js

function fibonnacci(n) {
  if (n === 0) {
    return 0;
  }
  else if (n === 1) {
    return 1;
  }
  else {
    return fibonnacci(n-1)+fibonnacci(n-2);
  }
}

// Values of the Fth number of the fibonnacci sequence
// F0: 0 ; F1: 1; F2: 1; F3: 2; F4: 3; F5: 5; F6: 8; F7: 13; F8: 21; 
// F9: 34; F10: 55; F11: 89; F12: 144; F13: 233; F14: 377; F15: 610; 
// F16:987; F17: 1597; F18: 2584; F19: 4181; F20: 6765;

var numb = 15; // should return 610
console.log(fibonnacci(numb));