Cast on a number of stitches in multiples of two to the desired size.
Row 1 and 3: (wrong side) K across.
Row 2: *K1, k next st by inserting needle in center of st in row below, knitting through both loops *; repeat between *s to within 2 sts of end, K2.
Row 4: K1; repeat between *s of row 2, end K1.
Repeat these 4 rows until desired length. Finish off.