## The challenge

Given the triangle of consecutive odd numbers:

```
1
3 5
7 9 11
13 15 17 19
21 23 25 27 29
...
```

Calculate the row sums of this triangle from the row index (starting at index 1) e.g.:

```
row_sum_odd_numbers(1); # 1
row_sum_odd_numbers(2); # 3 + 5 = 8
```

## Test cases

```
Test.assert_equals(row_sum_odd_numbers(1), 1)
Test.assert_equals(row_sum_odd_numbers(2), 8)
Test.assert_equals(row_sum_odd_numbers(13), 2197)
Test.assert_equals(row_sum_odd_numbers(19), 6859)
Test.assert_equals(row_sum_odd_numbers(41), 68921)
```

## The solution in code

While there are many ways to achieve this, the absolute most simple is to realise that the solution is just a `n^3`

.

```
def row_sum_odd_numbers(n):
return n*n*n
```

Another way is to do it the more Pythonic way:

```
def row_sum_odd_numbers(n):
return n ** 3
```