Shown with a cast-on count of 43 stitches.  

• Row 1 (RS): K5, *k2tog, yo, k1, yo, k2tog, k9, repeat from * to last 10 sts, k2tog, yo, k1, yo, k2tog, k5.
• Row 2: K4, *k2tog, yo, k3, yo, k2tog, k7, repeat from * to last 11 sts, k2tog, yo, k3, yo, k2tog, k4.
• Row 3: K3, *k2tog, yo, k5, yo, k2tog, k5, repeat from * to last 12 sts, k2tog, yo, k5, yo, k2tog, k3.
• Row 4: K2, *k2tog, yo, k1, k2tog, [yo] twice, k2tog, k2, yo, k2tog, k3, repeat from * to last 13 sts, k2tog, yo, k1, k2tog, [yo] twice, k2tog, k2, yo, k2tog, k2.