A146948 Semiprimes n such that n+1 and n+2 are squarefree.

4, 9, 21, 33, 57, 65, 69, 77, 85, 93, 121, 129, 141, 177, 185, 201, 209, 213, 217, 221, 237, 253, 265, 289, 301, 309, 321, 329, 365, 381, 393, 417, 437, 445, 453, 469, 481, 497, 501, 517, 533, 545, 553, 581, 589, 597, 633, 669, 681, 689, 697, 713, 717, 753