#1137 - N-th Tribonacci Number

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Problem Description

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.

Solution

/**
 * @param {number} n
 * @return {number}
 */
var tribonacci = function(n) {
  const nums = [0, 1, 1];

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

  return nums[n];
};