Shown with a cast-on count of 15 stitches.  

• Rows 1 and 5 (RS): *K1, p1, k1, p3, repeat from * to last 3 sts, k1, p1, k1.
• Rows 2 and 6: P1, k1, p1, *k3, p1, k1, p1, repeat from *.
• Rows 3, 7, 11, and 15: *K3, 3-to-3 gather, repeat from * to last 3 sts, k3.
• Rows 4, 8, 12, and 16: *P3, k3, repeat from * to last 3 sts, p3.
• Rows 9 and 13: *3-To-3 gather, k3, repeat from * to last 3 sts, 3-to-3 gather.
• Rows 10 and 14: K3, *p3, k3, repeat from *.