1137. N-th Tribonacci Number.js

// The Tribonacci sequence Tn is defined as follows:

// T0 = 0, T1 = 1, T2 = 1, and Tn+3 = Tn + Tn+1 + Tn+2 for n >= 0.

// Given n, return the value of Tn.

// Example 1:

// Input: n = 4
// Output: 4
// Explanation:
// T_3 = 0 + 1 + 1 = 2
// T_4 = 1 + 1 + 2 = 4
// Example 2:

// Input: n = 25
// Output: 1389537

const tribonacci = n => {
	let result = [0, 1, 1]

	for (let i = 3; i <= n; i++) {
		result[i] = result[i - 1] + result[i - 2] + result[i - 3]
	}

	return result[n]
}