[(1 dc, ch 1) 3 times, 1 dc]
(ch a multiple of 5 sts + 4)
Row 1 Work 1 dc in 4th ch from hook, *skip 4 ch, shell in next ch; rep from *, end last rep skip 4 ch, 2 dc in last ch. Turn.
Row 2 Ch 3 (counts as 1 dc), skip first dc, 1 dc in next dc, *shell in center ch-1 sp of shell; rep from *, end 2 dc in top of t-ch. Turn.
Rep row 2.
Stitch directions reproduced with permission, from Vogue Knitting Stitchionary: Volume Four, Sixth & Spring Books, 2007