Shown with a cast-on count of 15 stitches.  

• Row 1 (RS): K2, yo, k1, yo, k2, ssk, yo, p1, yo, k2tog, k2, yo, k1, yo, k2 (19 sts).
• Rows 2, 4, 6, 8, 10, 12, 14, 16, and 18: Purl.
• Row 3: K2, yo, k2, yo, ssk, k3, yo, p1, yo, k3, k2tog, yo, k2, yo, k2 (23 sts).
• Row 5: K2, yo, k1, ssk, yo, k6, yo, p1, yo, k6, yo, k2tog, k1, yo, k2 (27 sts).
• Row 7: K2, yo, [k1, yo, k2, ssk] twice, k1, yo, p1, yo, k1, [k2tog, k2, yo, k1] twice, yo, k2 (31 sts).
• Row 9: K2, yo, [k2, yo, ssk, k1] twice, k3, yo, p1, yo, k3, [k1, k2tog, yo, k2] twice, yo, k2 (35 sts).
• Row 11: K2, yo, [k1, ssk, yo, k2] 3 times, yo, p1, yo, [k2, yo, k2tog, k1] 3 times, yo, k2 (39 sts).
• Row 13: K2, yo, [k1, yo, k2, ssk] 3 times, k2, yo, p1, yo, k2, [k2tog, k2, yo, k1] 3 times, yo, k2 (43 sts).
• Row 15: K2, yo, [k2, yo, ssk, k1] 3 times, k4, yo, p1, yo, k4, [k1, k2tog, yo, k2] 3 times, yo, k2 (47 sts).
• Row 17: K2, yo, [k1, yo, k2, ssk] 4 times, k1, yo, p1, yo, k1, [k2tog, k2, yo, k1] 4 times, yo, k2 (51 sts).