The following function attempts to calculate the n th triangular number ( Tn ). The n th triangular number is defined by the formula: Tn=n+(n−1)+(n−2)+...+3+2+1 In other words, triangular numbers are just like factorial numbers, but with addition instead of multiplication. Below we've attempted to write a recursive formula that will calculate the n th triangular number. 1| def tri(n): 2| return n + tri(n - 1) What will be the current result of using this function?