Fibonacci series program

Is the problem solved by this program(I’m not looping until user wants to enter the value knowingly…)?

//Input initial size of green crud population and number of days
//Output to find pounds of green crud after that many days
let no_of_days = 25;
let initial_size = 10;
let a = [initial_size, initial_size];
for (i = 0; i < no_of_days / 5; i++) {
  a[i + 2] = a[i] + a[i + 1];
}
console.log(a);