斐波那契数列

求斐波那契数列的前20

已知：数列第一个数字是1，第二是2

let fibArr = [];
fibArr[1] = 1;
fibArr[2] = 2;

for (let i = 3; i < 20; i++) {
    fibArr[i] = fibArr[i - 1] + fibArr[i - 2]
}
console.log(fibArr)