Shown with a cast-on count of 21 stitches.  

• Row 1 (RS): K1, yo, sl1-k2tog-psso, yo, [k1, yo, sl2-k1-p2sso, yo] 3 times, k1, yo, k3tog, yo, k1.
• Rows 2, 14, 16, 18, 20, 22, and 24: Purl.
• Row 3: K1, [yo] twice, k1, yo, sl1-k2tog-psso, k11, k3tog, yo, k1, [yo] twice, k1 (23 sts).
• Row 4: P2, p1 tbl, p17, p1 tbl, p2.
• Row 5: K2, [yo] twice, k1, ssk, yo, sl1-k2tog-psso, yo, sl2-k1-p2sso, yo, k1, yo, sl2-k1-p2sso, yo, k3tog, yo, k2tog, k1, [yo] twice, k2.
• Row 6: P3, p1 tbl, p15, p1 tbl, p3.
• Row 7: K3, [yo] twice, k2, ssk, yo, sl1-k2tog-psso, k3, k3tog, yo, k2tog, k2, [yo] twice, k3.
• Row 8: P4, p1 tbl, p13, p1 tbl, p4.
• Row 9: K4, [yo] twice, k3, ssk, yo, k1, yo, sl2-k1-p2sso, yo, k1, yo, k2tog, k3, [yo] twice, k4 (27 sts).
• Row 10: P5, p1 tbl, p15, p1 tbl, p5.
• Row 11: K5, [yo] twice, k4, ssk, yo, k2tog, k1, ssk, yo, k2tog, k4, [yo] twice, k5 (29 sts).
• Row 12: P6, p1 tbl, p15, p1 tbl, p6.
• Row 13: K4, ssk, yo, k2tog, k3, ssk, yo, sl2-k1-p2sso, yo, k2tog, k3, ssk, yo, k2tog, k4 (25 sts).
• Row 15: K3, ssk, yo, k1, yo, k2tog, k2, ssk, yo, k1, yo, k2tog, k2, ssk, yo, k1, yo, k2tog, k3.
• Row 17: K2, ssk, yo, k3, yo, k2tog, k1, ssk, yo, k1, yo, k2tog, k1, ssk, yo, k3, yo, k2tog, k2.
• Row 19: K1, ssk, yo, k2tog, k1, ssk, yo, k2tog, ssk, yo, k1, yo, k2tog, ssk, yo, k2tog, k1, ssk, yo, k2tog, k1 (21 sts).
• Row 21: Ssk, [yo, k1, yo, sl2-k1-p2sso] twice, yo, k1, yo, [sl2-k1-p2sso, yo, k1, yo] twice, k2tog.
• Row 23: Knit.