find area of n-interesting polygon

I found the formula without the recursion. The test went through fine.

def shapeArea(n):
    if n>=10**4 or n<1:
        return False

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

As there are already coding examples, I will explain why the formula is n * n + (n-1) * (n-1)

1. You need to see the graph diagonally
2. You will notice that the sides are always n
3. For example, if n=4, the shape has for 4 squares on each side, thus n * n
4. However, if you notice, n * n does not account for all the squares. There are squares in between the once you accounted for
5. Take away the square you have accounted with n * n, you will notice now that the side of the shape is now n-1
6. Thus, you take into account of the squares in between, the formula is n * n + (n-1) * (n-1)
7. Example: if n = 4, the outer square is 4 * 4 = 16. Then take away the area you have just calculated, the inner squares is 3 * 3 = 9. Add together, you get 25.

The easiest solution to the problem in JavaScript:

function shapeArea(n) {
    if(n<0) {
        return false
    }
    return (n*n) + ((n-1)*(n-1))
}

console.log(shapeArea(1))

I think the last part where you have written the 'for' loop is dodgy. If you're already using recursion why do you need a 'for' loop? Nonetheless, I did it this way without using recursion:

def shapeArea(n):
if n == 1:
    return 1
return n**2 + (n-1)**2

This is a formula to find an area of polygon for given n

def shapeArea(n):
    return (n**2)+((n-1)**2)

shapeArea(3)

Output

13