Shown with a cast-on count of 37 stitches.  

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