Shown with a cast-on count of 13 stitches.  

• Rows 1 and 5 (RS): K1, *k1, k2tog, yo, k3, repeat from *.
• Rows 2 and 4: Purl.
• Rows 3 and 17: K1, *k2tog, yo, k1, yo, ssk, k1, repeat from *.
• Row 7: K1, *k2tog, yo, k1, yo, ssk, k1, repeat from *.
• Row 9: K1, *yo, k3, yo, sl1-k2tog-psso, repeat from *.
• Row 11: K1, *yo, ssk, k1, k2tog, yo, k1, repeat from *.
• Row 13: K1, *k1, yo, sl1-k2tog-psso, yo, k2, repeat from *.
• Rows 15 and 19: K1, *k1, k2tog, yo, k3, repeat from *.
• Row 20: Purl.