Shown with a cast-on count of 33 stitches.  

• Row 1 (RS): *K9, p3, repeat from * to last 9 sts, k9.
• Row 2: P9, *k3, p9, repeat from *.
• Row 3: *P1, k7, p4, repeat from * to last 9 sts, p1, k7, p1.
• Row 4: K1, p7, k1, *k4, p7, k1, repeat from *.
• Row 5: *P2, k5, p5, repeat from * to last 9 sts, p2, k5, p2.
• Row 6: K2, p5, k2, *k5, p5, k2, repeat from *.
• Row 7: *P3, k3, p6, repeat from * to last 9 sts, p3, k3, p3.
• Row 8: K3, p3, k3, *k6, p3, k3, repeat from *.
• Row 9: *P4, k1, p7, repeat from * to last 9 sts, p4, k1, p4.
• Row 10: K4, p1, k4, *k7, p1, k4, repeat from *.
• Row 11: *P9, k3, repeat from * to last 9 sts, p9.
• Row 12: K9, *p3, k9, repeat from *.
• Row 13: *K1, p7, k4, repeat from * to last 9 sts, k1, p7, k1.
• Row 14: P1, k7, p1, *p4, k7, p1, repeat from *.
• Row 15: *K2, p5, k5, repeat from * to last 9 sts, k2, p5, k2.
• Row 16: P2, k5, p2, *p5, k5, p2, repeat from *.
• Row 17: *K3, p3, k6, repeat from * to last 9 sts, k3, p3, k3.
• Row 18: P3, k3, p3, *p6, k3, p3, repeat from *.
• Row 19: *K4, p1, k7, repeat from * to last 9 sts, k4, p1, k4.
• Row 20: P4, k1, p4, *p7, k1, p4, repeat from *.