async await

upper.js

const upper = async function (n) {
  const list = []

  for(let i of new Array(n+1).join('.').split('').map((a,b) => b+1)){
    list.push(await new Promise(res => {
      if (list.length) 
        res(list.toString().split(',').pop()*2)
      else
        res(n)
    }))
  }
  
  return list
}

upper(50).then(console.log)

/*
 [50, 100, 200, 400, 800, 1600, 3200, 6400, 12800, 25600, 51200, 102400, 204800, 409600, 819200, 1638400, 3276800, 6553600, 13107200, 26214400, 52428800, 104857600, 209715200, 419430400, 838860800, 1677721600, 3355443200, 6710886400, 13421772800, 26843545600, 53687091200, 107374182400, 214748364800, 429496729600, 858993459200, 1717986918400, 3435973836800, 6871947673600, 13743895347200, 27487790694400, 54975581388800, 109951162777600, 219902325555200, 439804651110400, 879609302220800, 1759218604441600, 3518437208883200, 7036874417766400, 14073748835532800, 28147497671065600]
 */