Shown with a cast-on count of 41 stitches.  

• Row 1 (RS): K20, k1, k20.
• Rows 2, 4, 6, 8, 10, 12, 14, 16, 18, 20, 22, 24, 26, 28, 30, 32, 34, 36, 38, 40, 42, 44, 46, 48, 50, 52, 54, and 56: Purl.
• Row 3: K20, M1L, k1, M1R, k20 (43 sts).
• Row 5: K21, M1L, k1, M1R, k21 (45 sts).
• Row 7: K22, M1L, k1, M1R, k22 (47 sts).
• Row 9: K23, M1L, k1, M1R, k23 (49 sts).
• Row 11: K24, M1L, k1, M1R, k24 (51 sts).
• Row 13: K25, M1L, k1, M1R, k25 (53 sts).
• Row 15: K3, k2tog, k19, ssk, k1, k2tog, k19, ssk, k3 (49 sts).
• Row 17: K3, k2tog, k17, ssk, k1, k2tog, k17, ssk, k3 (45 sts).
• Row 19: K3, k2tog, k15, ssk, k1, k2tog, k15, ssk, k3 (41 sts).
• Row 21: K3, k2tog, k13, ssk, k1, k2tog, k13, ssk, k3 (37 sts).
• Row 23: K3, k2tog, k11, ssk, k1, k2tog, k11, ssk, k3 (33 sts).
• Row 25: K3, k2tog, k9, ssk, k1, k2tog, k9, ssk, k3 (29 sts).
• Row 27: K3, k2tog, k7, ssk, k1, k2tog, k7, ssk, k3 (25 sts).
• Row 29: K3, k2tog, k5, ssk, k1, k2tog, k5, ssk, k3 (21 sts).
• Row 31: K3, k2tog, k3, ssk, k1, k2tog, k3, ssk, k3 (17 sts).
• Row 33: K3, k2tog, k1, ssk, k1, k2tog, k1, ssk, k3 (13 sts).
• Row 35: K3, k2tog, k3, ssk, k3 (11 sts).
• Row 37: K3, k2tog, k1, ssk, k3 (9 sts).
• Row 39: K3, sl2-k1-p2sso, k3 (7 sts).
• Row 41: K2, sl2-k1-p2sso, k2 (5 sts).
• Row 43: K1, sl2-k1-p2sso, k1 (3 sts).
• Rows 45, 47, 49, 51, 53, and 55: K3.
• Row 58: Purl.