const fibonacciUntilNum = num => { let n = Math.ceil(Math.log(num * Math.sqrt(5) + 1 / 2) / Math.log((Math.sqrt(5) + 1) / 2)); return Array.from({ length: n }).reduce( (acc, val, i) => acc.concat(i > 1 ? acc[i - 1] + acc[i - 2] : i), [] ); }; module.exports = fibonacciUntilNum;