---
title: "LeetCode #1137: N-th Tribonacci Number"
url: https://perrotta.dev/2025/12/leetcode-%231137-n-th-tribonacci-number/
last_updated: 2026-01-03
---


[LeetCode #1137: N-th Tribonacci Number](https://leetcode.com/problems/n-th-tribonacci-number):

```python
class Solution:
    def tribonacci(self, n: int) -> int:
        from functools import cache

        @cache
        def tribo(n):
            if n == 0:
                return 0

            if n in (1, 2):
                return 1

            return tribo(n - 1) + tribo(n - 2) + tribo(n - 3)

        return tribo(n)
```