Shown with a cast-on count of 41 stitches.  

• Rows 1, 13, 15, 19, 21, and 23 (RS): Knit.
• Rows 2, 4, 14, and 16: Knit.
• Row 3: K3, [kfb, k9, kfb, k1] twice, kfb, k9, kfb, k3 (47 sts).
• Row 5: K3, [kfb, k11, kfb, k1] twice, kfb, k11, kfb, k3 (53 sts).
• Rows 6, 8, 10, 12, 18, 20, 22, and 24: K3, purl to last 3 sts, k3.
• Row 7: K3, yo, ssk, k3, k2tog, yo, k1, yo, ssk, k3, k2tog, yo, k1, yo, ssk, k3, k2tog, yo, k1, yo, ssk, k3, k2tog, yo, k1, yo, ssk, k3, k2tog, yo, k1, yo, ssk, k3, k2tog, yo, k3.
• Row 9: K3, kfb, yo, ssk, k1, k2tog, yo, k3, yo, ssk, k1, k2tog, yo, kfb, k1, kfb, yo, ssk, k1, k2tog, yo, k3, yo, ssk, k1, k2tog, yo, kfb, k1, kfb, yo, ssk, k1, k2tog, yo, k3, yo, ssk, k1, k2tog, yo, kfb, k3 (59 sts).
• Row 11: K3, kfb, k2, yo, sl1-k2tog-psso, yo, k5, yo, sl1-k2tog-psso, yo, k2, kfb, k1, kfb, k2, yo, sl1-k2tog-psso, yo, k5, yo, sl1-k2tog-psso, yo, k2, kfb, k1, kfb, k2, yo, sl1-k2tog-psso, yo, k5, yo, sl1-k2tog-psso, yo, k2, kfb, k3 (65 sts).
• Row 17: K3, [kfb, k17, kfb, k1] twice, kfb, k17, kfb, k3 (71 sts).