Shown with a cast-on count of 4 stitches.  

• Row 1 (RS): Kfb, p1, k1, k1 (5 sts).
• Row 2: Sl1 wyif, p1, k1, k1, kfb (6 sts).
• Row 3: Kfb, k2, p1, k1, k1 (7 sts).
• Row 4: Sl1 wyif, p1, k1, k3, kfb (8 sts).
• Row 5: Kfb, knit to last 5 sts, k2tog, p1, k1, k1.
• Rows 6 and 20: Sl1 wyif, p1, k1, knit to last st, kfb (1 more st).
• Row 7: Kfb, knit to last 5 sts, k2tog, p1, yo, k1, yo, k1 (2 more sts).
• Rows 8 and 18: Sl1 wyif, p3, k1, knit to last st, kfb (1 more st).
• Row 9: Kfb, knit to last 7 sts, k2tog, p1, k1, yo, k1, yo, k1, k1 (2 more sts).
• Rows 10 and 16: Sl1 wyif, p5, k1, knit to last st, kfb (1 more st).
• Row 11: Kfb, knit to last 9 sts, k2tog, p1, k2, yo, k1, yo, k2, k1 (2 more sts).
• Rows 12 and 14: Sl1 wyif, p7, k1, knit to last st, kfb (1 more st).
• Row 13: Kfb, knit to last 11 sts, k2tog, p1, k7, k1.
• Row 15: Kfb, knit to last 11 sts, k2tog, p1, ssk, k3, k2tog, k1 (2 fewer sts).
• Row 17: Kfb, knit to last 9 sts, k2tog, p1, ssk, k1, k2tog, k1 (2 fewer sts).
• Row 19: Kfb, knit to last 7 sts, k2tog, p1, sl1-k2tog-psso, k1 (2 fewer sts).
• Repeat rows 5-20.