Shown with a cast-on count of 37 stitches.  

• Rows 1 and 9 (RS): K1, *k2, yo, k2, sl2-k1-p2sso, k2, yo, k3, repeat from *.
• Rows 2, 4, 6, 8, 10, 12, 14, 16, 18, and 20: Purl.
• Rows 3 and 7: K1, *k1, yo, k2, ssk, k1, k2tog, k2, yo, k2, repeat from *.
• Row 5: K1, *yo, k2, ssk, k3, k2tog, k2, yo, k1, repeat from *.
• Rows 11 and 19: K2tog, *k2, yo, k5, yo, k2, sl2-k1-p2sso, repeat from * to last 11 sts, k2, yo, k5, yo, k2, ssk.
• Rows 13 and 17: K1, *k2tog, k2, yo, k3, yo, k2, ssk, k1, repeat from *.
• Row 15: K1, *k1, k2tog, k2, yo, k1, yo, k2, ssk, k2, repeat from *.