16-bit seed PRNG. period=65534. uniform-ish looking distribution https://i.imgur.com/kKI5W2s.png

prng16.c

typedef unsigned short u16;

u16 random_u16(void) {
  static u16 s;

  s ^= s << 8;
  s = ((s & 0xFF) << 1) ^ ((s << 8) | (s >> 8));
  s = 38607*s + 35335;
  s = (s >> 1) ^ (-(~s & 1) & 0x9E74) ^ 0x7E00;

  return s;
}