Shown with a cast-on count of 57 stitches.  

• Row 1 (RS): K10, *k2tog, yo, k1, yo, ssk, k11, repeat from * to last 15 sts, k2tog, yo, k1, yo, ssk, k10.
• Rows 2, 4, 6, 8, 10, 12, 14, and 16: Purl.
• Row 3: K9, *k2tog, yo, k3, yo, ssk, k9, repeat from *.
• Row 5: K10, *yo, ssk, yo, k3tog, yo, k11, repeat from * to last 15 sts, yo, ssk, yo, k3tog, yo, k10.
• Row 7: K11, *yo, sl1-k2tog-psso, yo, k13, repeat from * to last 14 sts, yo, sl1-k2tog-psso, yo, k11.
• Row 9: K2, *k2tog, yo, k1, yo, ssk, k11, repeat from * to last 7 sts, k2tog, yo, k1, yo, ssk, k2.
• Row 11: K1, *k2tog, yo, k3, yo, ssk, k9, repeat from * to last 8 sts, k2tog, yo, k3, yo, ssk, k1.
• Row 13: K2, *yo, ssk, yo, k3tog, yo, k11, repeat from * to last 7 sts, yo, ssk, yo, k3tog, yo, k2.
• Row 15: K3, *yo, sl1-k2tog-psso, yo, k13, repeat from * to last 6 sts, yo, sl1-k2tog-psso, yo, k3.