rand31.js

export default createFromSeed(randomSeed());

export function createFromSeed(seed) {
  if (!Number.isInteger(seed) || seed <= 0) {
    throw new TypeError('seed must be an int > 0');
  }

  let value = seed;
  const next = () => {
    const hi = 16807 * (value >> 16);
    const lo = 16807 * (value & 0xFFFF) + ((hi & 0x7FFF) << 16) + (hi >> 15);
    value = lo > 0x7fffffff ? lo - 0x7fffffff : lo;
  };

  return max => Math.floor(next() / 0x7fffffff * max);
}

export function randomSeed() {
  return 1 + Math.floor(Math.random() * (Number.MAX_SAFE_INTEGER - 1));
}

http://www.firstpr.com.au/dsp/rand31/