The challenge
Given the triangle of consecutive odd numbers:
1
2
3
4
5
6

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.:
1
2

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

Test cases
1
2
3
4
5

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
.
1
2

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

Another way is to do it the more Pythonic way:
1
2

def row_sum_odd_numbers(n):
return n ** 3
