Shown with a cast-on count of 37 stitches.  

• Row 1 (RS): K1, *yo, ssk, k7, k2tog, yo, k1, repeat from *.
• Rows 2, 4, 6, 8, 10, 12, 14, 16, 18, and 20: Purl.
• Row 3: K1, *k1, yo, ssk, k5, k2tog, yo, k2, repeat from *.
• Row 5: K1, *[yo, ssk] twice, k3, [k2tog, yo] twice, k1, repeat from *.
• Row 7: K1, *k1, [yo, ssk] twice, k1, [k2tog, yo] twice, k2, repeat from *.
• Row 9: K1, *[yo, ssk] twice, yo, sl1-k2tog-psso, yo, [k2tog, yo] twice, k1, repeat from *.
• Row 11: K1, *k3, k2tog, yo, k1, yo, ssk, k4, repeat from *.
• Row 13: K1, *k2, k2tog, yo, k3, yo, ssk, k3, repeat from *.
• Row 15: K1, *k1, [k2tog, yo] twice, k1, [yo, ssk] twice, k2, repeat from *.
• Row 17: K1, *[k2tog, yo] twice, k3, [yo, ssk] twice, k1, repeat from *.
• Row 19: K2tog, yo, *[k2tog, yo] twice, k1, [yo, ssk] twice, yo, sl1-k2tog-psso, yo, repeat from * to last 11 sts, [k2tog, yo] twice, k1, [yo, ssk] 3 times.