**Question:**\nGiven a non-negative integer `n`, write a function to test if that `n` is a Fibonacci number.\n\n**Example 1:**\n```\nInput: n = 13\nOutput: true\n```\n\n**Example 2:**\n```\nInput: n = 20\nOutput: false\n```\n\n\n---\n**Follow-up:**\nAll positive integer numbers can be represented as a sum of Fibonacci numbers. Given a non-negative integer `n`, find any minimum combination of Fibonacci numbers required that sums up to a given number `n`.\n\n**Example 1:**\n```\nInput: n = 14\nOutput: [1, 13]\nExplanation: 1+13, 8+5+1, 3+5+5+1 and many others can sum up to 14, but minimum number of terms required are 2.\n```\n\n**Example 2:**\n```\nInput: n = 17\nOutput: [1, 3, 13] or [8, 8, 1] or [13, 2, 2]\nExplanation: 1+3+13, 8+8+1, 13+2+2 all sum up to 17 and 3 is minimum number of terms required so you can return any of them.\n```\n\n**Example 3:**\n```\nInput: n = 20\nOutput: [13, 5, 2]\n```\n\n---\n\nRelated problems:\n* https://leetcode.com/problems/find-the-minimum-number-of-fibonacci-numbers-whose-sum-is-k/

Question:\nGiven a non-negative integer n, write a function to test if that n is a Fibonacci number.\n\nExample 1:\n\nInput: n = 13\nOutput: true\n\n\nExample 2