I am knitting a Rowan pattern and need help from someone who understands complicated knitting. Here is the problem:
I have 259 purl stitches on the needles (and this is correct per the pattern). A marker has been placed to denote location of future side seam. The instructions for the row I need to complete are as follows (note that “patt” just means to Purl for those sts):
Round 17 (RS): P2, P2tog, patt to within 4 sts of marker, P2tog tbl, P4 (marker is at center of these 4 sts), P2tog, patt to last 4 sts, P2tog tbl, P2.  sts.
The problem is that, if I follow the instructions, there are 4 times that I am required to P2 together. Thus, the row is decreased by 4 stitches, leaving 255 stitches in the row, NOT 258 as indicated.
Can someone help me understand why the instructions indicate that the row will go from 259 to 258 stitches, a reduction of only 1 stitch???