Shown with a cast-on count of 52 stitches.  

• Rows 1 and 21 (RS): [P2, k2] twice, [p2, k2] 9 times, [p2, k2] twice.
• Row 2: [P2, k2] twice, [p2, k2] 9 times, [p2, k2] twice.
• Row 3: [P2, k2] twice, [p2, k2] 9 times, turn (44 sts).
• Rows 4 and 18: [P2, k2] 9 times, turn (36 sts).
• Rows 5 and 17: [P2, k2] 8 times, turn (32 sts).
• Rows 6 and 16: [P2, k2] 7 times, turn (28 sts).
• Rows 7 and 15: [P2, k2] 6 times, turn (24 sts).
• Rows 8 and 14: [P2, k2] 5 times, turn (20 sts).
• Rows 9 and 13: [P2, k2] 4 times, turn (16 sts).
• Row 10: [P2, k2] 3 times, turn (12 sts).
• Row 11: [P2, k2] 3 times, turn.
• Row 12: [P2, k2] 3 times, turn.
• Row 19: [P2, k2] twice, [p2, k2] 9 times (44 sts).
• Row 20: [P2, k2] twice, [p2, k2] 9 times, [p2, k2] twice (52 sts).