Shown with a cast-on count of 25 stitches.  

• Row 1 (RS): K1, kfb, *k2, k2tog, yo, k1, yo, ssk, k2, repeat from * to last 5 sts, k2, k2tog, k1.
• Row 2: K4, *k9, repeat from * to last 3 sts, k1, kfb, k1 (multiple of 9 sts, plus 8).
• Row 3: K1, kfb, k2, *k1, k2tog, yo, k3, yo, ssk, k1, repeat from * to last 4 sts, k1, k2tog, k1.
• Row 4: K3, *k9, repeat from * to last 5 sts, k3, kfb, k1 (multiple of 9 sts, plus 9).
• Row 5: K1, kfb, k2, yo, ssk, *k2tog, yo, k1, yo, sl1-k2tog-psso, yo, k1, yo, ssk, repeat from * to last 3 sts, k2tog, k1.
• Row 6: K2, *k9, repeat from * to last 7 sts, k5, kfb, k1 (multiple of 9 sts, plus 10).
• Row 7: K1, kfb, k1, *k1, yo, ssk, k4, k2tog, yo, repeat from * to last 7 sts, k1, yo, ssk, k1, k2tog, k1.
• Row 8: K6, *k9, repeat from * to last 4 sts, k2, kfb, k1 (multiple of 9 sts, plus 11).
• Row 9: K1, kfb, k2tog, yo, k1, *k2, yo, ssk, k2, k2tog, yo, k1, repeat from * to last 6 sts, k3, k2tog, k1.
• Row 10: K5, *k9, repeat from * to last 6 sts, k4, kfb, k1 (multiple of 9 sts, plus 12).
• Row 11: K1, kfb, k1, k2tog, yo, k1, yo, *sl1-k2tog-psso, yo, k1, yo, ssk, k2tog, yo, k1, yo, repeat from * to last 6 sts, sl1-k2tog-psso, yo, k2tog, k1.
• Row 12: K4, *k9, repeat from * to last 8 sts, k6, kfb, k1 (multiple of 9 sts, plus 13).
• Row 13: K1, kfb, k2, *k3, k2tog, yo, k1, yo, ssk, k1, repeat from * to last 9 sts, k3, k2tog, yo, k1, k2tog, k1.
• Row 14: K8, *k9, repeat from * to last 5 sts, k3, kfb, k1 (multiple of 9 sts, plus 14).
• Row 15: K1, kfb, k2, yo, ssk, *k2, k2tog, yo, k3, yo, ssk, repeat from * to last 8 sts, k2, k2tog, yo, k1, k2tog, k1.
• Row 16: K7, *k9, repeat from * to last 7 sts, k5, kfb, k1 (multiple of 9 sts, plus 15).
• Row 17: K1, kfb, k1, yo, sl1-k2tog-psso, yo, k1, yo, *ssk, k2tog, yo, k1, yo, sl1-k2tog-psso, yo, k1, yo, repeat from * to last 8 sts, ssk, k2tog, yo, k1, k2tog, k1.
• Row 18: K6, *k9, repeat from * to last 9 sts, k7, kfb, k1 (multiple of 9 sts, plus 16).