Shown with a cast-on count of 41 stitches.  

• Row 0 (RS): K41.
• Row 1: K2, (k1, p1, k1) in next st, [k2, yo, k2tog] 8 times, k3, k3tog.
• Row 2: [K2, yo, k2tog] 8 times, k1, k3tog, k2, yo, k2tog, (k1, p1, k1) in next st.
• Row 3: K2, yo, k2tog, k2, (k1, p1, k1) in next st, [k2, yo, k2tog] 7 times, k3, k3tog.
• Row 4: [K2, yo, k2tog] 7 times, k1, k3tog, [k2, yo, k2tog] twice, (k1, p1, k1) in next st.
• Row 5: [K2, yo, k2tog] twice, k2, (k1, p1, k1) in next st, [k2, yo, k2tog] 6 times, k3, k3tog.
• Row 6: [K2, yo, k2tog] 6 times, k1, k3tog, [k2, yo, k2tog] 3 times, (k1, p1, k1) in next st.
• Row 7: [K2, yo, k2tog] 3 times, k2, (k1, p1, k1) in next st, [k2, yo, k2tog] 5 times, k3, k3tog.
• Row 8: [K2, yo, k2tog] 5 times, k1, k3tog, [k2, yo, k2tog] 4 times, (k1, p1, k1) in next st.
• Row 9: [K2, yo, k2tog] 4 times, k2, (k1, p1, k1) in next st, [k2, yo, k2tog] 4 times, k3, k3tog.
• Row 10: [K2, yo, k2tog] 4 times, k1, k3tog, [k2, yo, k2tog] 5 times, (k1, p1, k1) in next st.
• Row 11: [K2, yo, k2tog] 5 times, k2, (k1, p1, k1) in next st, [k2, yo, k2tog] 3 times, k3, k3tog.
• Row 12: [K2, yo, k2tog] 3 times, k1, k3tog, [k2, yo, k2tog] 6 times, (k1, p1, k1) in next st.
• Row 13: [K2, yo, k2tog] 6 times, k2, (k1, p1, k1) in next st, [k2, yo, k2tog] twice, k3, k3tog.
• Row 14: [K2, yo, k2tog] twice, k1, k3tog, [k2, yo, k2tog] 7 times, (k1, p1, k1) in next st.
• Row 15: [K2, yo, k2tog] 7 times, k2, (k1, p1, k1) in next st, k2, yo, k2tog, k3, k3tog.
• Row 16: K2, yo, k2tog, k1, k3tog, [k2, yo, k2tog] 8 times, (k1, p1, k1) in next st.
• Row 17: [K2, yo, k2tog] 8 times, k2, (k1, p1, k1) in next st, k3, k3tog.
• Row 18: K1, k3tog, [k2, yo, k2tog] 9 times, (k1, p1, k1) in next st.