A048126 Becomes prime or 4 after exactly 4 iterations of f(x) = sum of prime factors of x.

26, 33, 39, 44, 49, 51, 55, 65, 66, 70, 77, 78, 84, 91, 92, 95, 98, 100, 105, 110, 112, 114, 119, 120, 125, 126, 128, 129, 130, 132, 135, 140, 143, 144, 150, 154, 156, 160, 162, 168, 170, 180, 189, 192, 196, 200, 204, 205, 216, 217, 220, 225, 240, 242, 243