Shown with a cast-on count of 18 stitches.  

• Rows 1 and 3 (RS): [K2, p2] 4 times, k2.
• Rows 2 and 4: P2, [k2, p2] 4 times.
• Row 5: K2, p2, k2, p2, incR, k2, incL, p2, k2, p2, k2 (20 sts).
• Row 6: P2, k2, p2, k2, p4, k2, p2, k2, p2.
• Row 7: [K2, p2] twice, 2/2 LC, [p2, k2] twice.
• Row 8: P2, k6, p4, k6, p2.
• Row 9: K2, p4, 2/2 RC, 2/2 LC, p4, k2.
• Row 10: P2, k4, p8, k4, p2.
• Row 11: K2, p2, 2/2 RPC, k4, 2/2 LPC, p2, k2.
• Row 12: K4, p2, k2, p4, k2, p2, k4.
• Row 13: P3, 2/1 RPC, p2, 2/2 LC, p2, 2/1 LPC, p3.
• Row 14: K3, p2, k3, p4, k3, p2, k3.
• Row 15: P2, 2/1 RPC, p3, k4, p3, 2/1 LPC, p2.
• Rows 16 and 18: K2, p2, k4, p4, k4, p2, k2.
• Row 17: P2, k2, p4, 2/2 LC, p4, k2, p2.
• Row 19: P2, 2/2 LPC, 2/2 RC, 2/2 LC, 2/2 RPC, p2.
• Row 20: K4, p12, k4.
• Row 21: P4, 2/2 RPC, k4, 2/2 LPC, p4.
• Repeat rows 12-21.