A048168 n is divisible by the square of the number of unitary divisors of n (A034444).

1, 4, 8, 16, 32, 48, 64, 80, 96, 112, 128, 144, 160, 176, 192, 208, 224, 256, 272, 288, 304, 320, 352, 368, 384, 400, 416, 432, 448, 464, 496, 512, 544, 576, 592, 608, 640, 656, 688, 704, 736, 752, 768, 784, 800, 832, 848, 864, 896, 928, 944, 960, 976, 992