Shown with a cast-on count of 31 stitches.  

• Row 1 (RS): K13, ssk, k1, k2tog, k13 (29 sts).
• Rows 2, 4, 6, 8, 10, 12, 14, 16, 18, 20, 22, 24, 26, and 28: Purl.
• Row 3: K12, ssk, k1, k2tog, k12 (27 sts).
• Row 5: K11, ssk, k1, k2tog, k11 (25 sts).
• Row 7: K10, ssk, k1, k2tog, k10 (23 sts).
• Row 9: K9, ssk, k1, k2tog, k9 (21 sts).
• Row 11: K8, ssk, k1, k2tog, k8 (19 sts).
• Row 13: K7, ssk, k1, k2tog, k7 (17 sts).
• Row 15: K6, ssk, k1, k2tog, k6 (15 sts).
• Row 17: K5, ssk, k1, k2tog, k5 (13 sts).
• Row 19: K4, ssk, k1, k2tog, k4 (11 sts).
• Row 21: K3, ssk, k1, k2tog, k3 (9 sts).
• Row 23: K2, ssk, k1, k2tog, k2 (7 sts).
• Row 25: K1, ssk, k1, k2tog, k1 (5 sts).
• Row 27: Ssk, k1, k2tog (3 sts).
• Row 29: K3tog (1 st).