N-th Tribonacci Number
Problem Statement
The Tribonacci sequence extends the Fibonacci concept by summing the three previous numbers instead of two. The sequence is defined as:
- T(0) = 0
- T(1) = 1
- T(2) = 1
- For n ≥ 3: T(n) = T(n-1) + T(n-2) + T(n-3)
Given an integer n, return the value of T(n).
Input Format
A single integer n where 0 ≤ n ≤ 37.
Output Format
A single integer representing T(n).
Examples
Example 1:
Input: n = 4 Output: 4
The sequence starts: 0, 1, 1, 2, 4, 7, 13, 24... T(4) = T(3) + T(2) + T(1) = 2 + 1 + 1 = 4
Example 2:
Input: n = 25 Output: 1389537