Please note the following corrections (deletions in red and additions in green):

BLANKET
With US 9 (5.5mm) needles cast on 171 169 sts and work as follows...

Next row: Patt as set 23 sts, (row 2 of pattern), purl to the last 23sts patt, as set the remaining 23sts (row 2 of pattern)
Note: the edge 23sts on each side are worked in pattern as set on rows 2 and 3:
Rep the last 2 rows 3 times more. ***