RandomShuffleSequence.cs

    class RandomShuffleSequence
    {
        public static int Shuffled(int cycleLength, int seed, int index)
        {
            int shuffleRange = cycleLength;
            int output = index % shuffleRange;
            int cycleIndex = index / cycleLength;

            while (output < shuffleRange)
            {
                output = (output + cycleIndex + seed) % shuffleRange;
                shuffleRange--;
            }

            return output;
        }
    }

Shuffler.js

var Shuffler = function(cycleLength, seed, index){
  var shuffleRange = cycleLength;
  var output = index % shuffleRange;
  var cycleIndex = index / cycleLength >> 0;
  while( output < shuffleRange ){
    output = (output + cycleIndex + seed) % shuffleRange;
    shuffleRange--;
  }
  return output;
}