Shown with a cast-on count of 20 stitches.  

• Row 1 (RS): P8, k4, p8.
• Row 2: K8, p4, k8.
• Row 3: P7, 2/1 RPC, 2/1 LC, p7.
• Rows 4 and 24: K7, p2, k1, p3, k7.
• Row 5: P6, 2/1 RC, p1, k1, 2/1 LPC, p6.
• Rows 6 and 22: K6, p3, k1, p1, k1, p2, k6.
• Row 7: P5, 2/1 RPC, [k1, p1] twice, 2/1 LC, p5.
• Rows 8 and 20: K5, p2, [k1, p1] twice, k1, p3, k5.
• Row 9: P4, 2/1 RC, [p1, k1] 3 times, 2/1 LPC, p4.
• Rows 10 and 18: K4, p3, [k1, p1] 3 times, k1, p2, k4.
• Row 11: P3, 2/1 RPC, [k1, p1] 4 times, 2/1 LC, p3.
• Rows 12 and 16: K3, p2, [k1, p1] 4 times, k1, p3, k3.
• Row 13: P2, 2/1 RPC, [p1, k1] 5 times, 2/1 LPC, p2.
• Row 14: K2, p3, [k1, p1] 5 times, k1, p2, k2.
• Row 15: P2, 2/1 LPC, [p1, k1] 5 times, 2/1 RPC, p2.
• Row 17: P3, 2/1 LPC, [k1, p1] 4 times, 2/1 RPC, p3.
• Row 19: P4, 2/1 LPC, [p1, k1] 3 times, 2/1 RPC, p4.
• Row 21: P5, 2/1 LPC, [k1, p1] twice, 2/1 RPC, p5.
• Row 23: P6, 2/1 LPC, p1, k1, 2/1 RPC, p6.
• Row 25: P7, 2/1 LPC, 2/1 RPC, p7.
• Repeat rows 2-25.