Shown with a cast-on count of 11 stitches.  

• Row 1 (RS): K4, yo, k1, yo, k1, yo, k1, yo, k1, sl3 wyib (15 sts).
• Rows 2, 4, 6, 8, 10, 12, 14, 16, 18, and 20: K3, purl to last 3 sts, sl3 wyif.
• Row 3: K4, yo, k3, yo, k1, yo, k3, yo, k1, sl3 wyib (19 sts).
• Row 5: K4, yo, k5, yo, k1, yo, k5, yo, k1, sl3 wyib (23 sts).
• Row 7: K4, yo, k7, yo, k1, yo, k7, yo, k1, sl3 wyib (27 sts).
• Row 9: K4, yo, k9, yo, k1, yo, k9, yo, k1, sl3 wyib (31 sts).
• Row 11: K4, yo, k11, yo, k1, yo, k11, yo, k1, sl3 wyib (35 sts).
• Row 13: K4, yo, k13, yo, k1, yo, k13, yo, k1, sl3 wyib (39 sts).
• Row 15: K4, yo, k15, yo, k1, yo, k15, yo, k1, sl3 wyib (43 sts).
• Row 17: K4, yo, k17, yo, k1, yo, k17, yo, k1, sl3 wyib (47 sts).
• Row 19: K4, yo, k19, yo, k1, yo, k19, yo, k1, sl3 wyib (51 sts).
• Row 21: K4, yo, k21, yo, k1, yo, k21, yo, k1, sl3 wyib (55 sts).