Start with the foundation chain: 53 ch.
R1: From 2nd st of hook: 52 sc.
R2: work 5 ch, turn, 1 dc, { sk 2, (in the same st: 1 dc, 2 ch, 1 dc) }*17 times.
R3: 3 ch, turn, work in the hole of sk2 in the previous row: (2 dc, 2 ch, 2 dc)*18 times.
R4: Turn, (work 1 ch, 8 dc in the hole in the previous row, 1 ss in the middle gap of the previous row of dc)*18 times. Then work 1 ch, cut and hide the tail.