strange links

hello
i just don’t understand – when i started to post new posts, the links started from some more than 400 – i mean i have about 70 posts total, but the last links are (yeah, in thislike order):
=543
=546
=560
=564

i thought, maybe it is cause of the attachments? i mean some thumbnail stuff?

btw, same with pages: page_id: 132, 134, 136… (first, some stranger order, second – i have just 9 pages at all!)