(ch a multiple of 2 sts + 4)
Row 1 1 Dc in 4th ch from hook, *ch 1, skip 1 ch, 1 dc in next ch; rep from * to end. Turn.
Row 2 Ch 3, 1 dc in first ch-1 sp, *ch 1, 1 dc in next ch-1 sp; rep from *, end ch 1, 1 dc in top of t-ch ch of row below. Turn.
Rep row 2.