A109412 Semiprimes = one-term groups in the partition of the sequence of natural numbers A109411.
4, 9, 10, 21, 22, 39, 49, 62, 69, 74, 93, 94, 95, 106, 111, 115, 146, 159, 203, 218, 219, 247, 254, 259, 295, 309, 319, 326, 327, 346, 355, 358, 394, 395, 398, 403, 427, 445, 446, 447, 451, 454, 551, 581, 586, 611, 622, 623, 671, 674, 679, 687, 694, 695, 698
Offset: 1