Shown with a cast-on count of 90 stitches.  

• Row 1 (RS): [P1, k1] 9 times, [p3, k3] 9 times, [p1, k1] 9 times.
• Rows 2 and 24: [P1, k1] 9 times, [p3, k3] 9 times, [p1, k1] 9 times.
• Row 3: [P1, k1] 9 times, [p3, k3] 9 times, turn (72 sts).
• Row 4: [P3, k3] 9 times, turn (54 sts).
• Row 5: [P3, k3] 8 times, turn (48 sts).
• Row 6: [P3, k3] 7 times, turn (42 sts).
• Row 7: [P3, k3] 6 times, turn (36 sts).
• Row 8: [P3, k3] 5 times, turn (30 sts).
• Row 9: [P3, k3] 4 times, turn (24 sts).
• Row 10: [P3, k3] 3 times, turn (18 sts).
• Row 11: [P3, k3] twice, turn (12 sts).
• Row 12: P3, k3, turn (6 sts).
• Row 13: P3, k3, turn.
• Row 14: [P3, k3] twice, turn (12 sts).
• Row 15: [P3, k3] 3 times, turn (18 sts).
• Row 16: [P3, k3] 4 times, turn (24 sts).
• Row 17: [P3, k3] 5 times, turn (30 sts).
• Row 18: [P3, k3] 6 times, turn (36 sts).
• Row 19: [P3, k3] 7 times, turn (42 sts).
• Row 20: [P3, k3] 8 times, turn (48 sts).
• Row 21: [P3, k3] 9 times, turn (54 sts).
• Row 22: [P3, k3] 9 times, [p1, k1] 9 times (72 sts).
• Row 23: [P1, k1] 9 times, [p3, k3] 9 times, [p1, k1] 9 times (90 sts).