(() => {
  const pi2 = Math.PI * 2
  const getRingSize = (ring) => ring === 0 ? 1 : ring * 8
  let getRingStart = (ring) => {
    if(ring === 0) return 0
    let currSum = 0
    for(let i = 1; i < ring; i++) currSum += i * 8
    return currSum + 2
  }
  const getAngle = (dX, dY) => (Math.atan2(dY, dX) + pi2) % pi2

  const getCoords = (n) => {
    if(n === 1) return [0, 0]
    let ring = 1
    while(getRingStart(ring + 1) <= n) ring += 1
    const ringSize = getRingSize(ring)
    const ringPos = n - getRingStart(ring)
    const angle = ((ringPos / ringSize) - (ring - 1) / ringSize) * pi2
    const opposite = Math.abs((ringPos % (ring * 2)) - (ring - 1))
    const diag = Math.sqrt(Math.pow(ring, 2) + Math.pow(opposite, 2))
    return [
      Math.round(Math.cos(angle) * diag) + 0,
      Math.round(Math.sin(angle) * diag) + 0
    ]
  }
  const cache = {}
  const getIndex = (() => (x, y) => {
    const cacheKey = `${x}/${y}`
    if(x === 0 && y === 0) return 1
    if(cache[cacheKey]) return cache[cacheKey]
    const ring = Math.max(Math.abs(x), Math.abs(y))
    const ringAdjust = ring - 1
    const ringSize = getRingSize(ring)
    const ringStart = getRingStart(ring)
    const angle = getAngle(x, y)
    const ringPos = (Math.round((angle / pi2) * ringSize) + ringAdjust) % ringSize
    return cache[cacheKey] = ringStart + ringPos
  })()

  const getAdjacent = (n) => {
    const [x, y] = getCoords(n)
    const adj = [
      [x - 1, y + 1], [x, y + 1], [x + 1, y + 1],
      [x - 1, y]                , [x + 1, y],
      [x - 1, y - 1], [x, y - 1], [x + 1, y - 1],
    ]
    return adj.map(([x, y]) => getIndex(x, y))
  }

  const cache2 = []
  const calcIndex = (index) => {
    if(index === 1) return 1
    if(cache2[index]) return cache2[index]
    const adjacent = getAdjacent(index).filter((adjIndex) => adjIndex <= index).sort((a, b) => a < b ? -1 : 1)

    return cache2[index] = adjacent.reduce((sum, adjIndex) => { return sum + calcIndex(adjIndex)}, 0)
  }


  let i = 0, result
  console.time('run')
  while((result = calcIndex(++i)) < 289326) {}
  console.timeEnd('run')
  console.log(result)

})()