Rnd 1: 

ch 3, 11 dc, join; 12 sts

Rnd 2:

ch 3, (ch 1, 1 dc) in ea st around, ch 1; 24 sts

Rnd 3:

ch 3, (ch 1, 1 dc) in ea st around, ch 1; 48 sts

Rnd 4:

rep Rnd 2

Rnd 5:

ch 3, (ch 2, 1 dc) in ea dc around, ch 2; 72 sts

Rnd 6:

sl st in ch sp, ch 3, 2dc in same sp, 3 dc in each ch sp around

Rnd 7:

ch 3, (ch 3, skip 2 dc, dc in next dc) around, ch 3

Rnd 8:

sl st in ch sp, ch 2, 1 dc, 2 tr, 1 dc, 1 sc, (1 sc, 1, dc, 2 tr, 1 dc, 1 sc) in ea ch sp around, join with sl st in last ch