Shown with a cast-on count of 21 stitches.  

• Rows 1 and 9 (RS): Ssk, k3, yo, k1, yo, k3, sl1-k2tog-psso, k3, yo, k1, yo, k3, k2tog.
• Rows 2, 4, 6, 8, 10, and 12: P21.
• Rows 3 and 11: Ssk, k2, yo, k3, yo, k2, sl1-k2tog-psso, k2, yo, k3, yo, k2, k2tog.
• Row 5: Ssk, k1, yo, k5, yo, k1, sl1-k2tog-psso, k1, yo, k5, yo, k1, k2tog.
• Row 7: Ssk, yo, k7, yo, sl1-k2tog-psso, yo, k7, yo, k2tog.