Shown with a cast-on count of 65 stitches.  

• Row 1 (RS): Purl.
• Rows 2 and 20: Knit.
• Row 3: K2, *k1, yo, k8, sl1-k2tog-psso, k8, yo, repeat from * to last 3 sts, k3.
• Rows 4, 6, 8, 10, 12, 14, 16, and 18: Purl.
• Row 5: K2, *k2, yo, k7, sl1-k2tog-psso, k7, yo, k1, repeat from * to last 3 sts, k3.
• Row 7: K2, k2tog, *yo, k1, yo, k6, sl1-k2tog-psso, k6, yo, k1, yo, sl1-k2tog-psso, repeat from * to last 21 sts, yo, k1, yo, k6, sl1-k2tog-psso, k6, yo, k1, yo, ssk, k2.
• Row 9: K2, *k4, yo, k5, sl1-k2tog-psso, k5, yo, k3, repeat from * to last 3 sts, k3.
• Row 11: K2, *k1, yo, sl1-k2tog-psso, yo, k1, yo, k4, sl1-k2tog-psso, k4, yo, k1, yo, sl1-k2tog-psso, yo, repeat from * to last 3 sts, k3.
• Row 13: K2, *k6, yo, k3, sl1-k2tog-psso, k3, yo, k5, repeat from * to last 3 sts, k3.
• Row 15: K2, k2tog, *yo, k1, yo, sl1-k2tog-psso, yo, k1, yo, k2, sl1-k2tog-psso, k2, [yo, k1, yo, sl1-k2tog-psso] twice, repeat from * to last 21 sts, yo, k1, yo, sl1-k2tog-psso, yo, k1, yo, k2, sl1-k2tog-psso, k2, yo, k1, yo, sl1-k2tog-psso, yo, k1, yo, ssk, k2.
• Row 17: K2, *k8, yo, k1, sl1-k2tog-psso, k1, yo, k7, repeat from * to last 3 sts, k3.
• Row 19: K2, *[k1, yo, sl1-k2tog-psso, yo] 5 times, repeat from * to last 3 sts, k3.