Chain multiple: 3 + 2

Stitch Guide

Front-post double crochet (FPdc): YO; insert hook from front to back to front around post (vertical bar) of specified st and draw up a lp; (YO and draw through 2 lps on hook) twice: FPdc made.

Back-post double crochet (BPdc): YO; insert hook from back to front to back around post (vertical bar) of specified st and draw up a lp; (YO and draw through 2 lps on hook) twice; BPdc made.

Instructions

Row 1: Sc in 2nd ch from hook and in each rem ch; ch 3 (counts as first dc of following row), turn.

Row 2 (RS): *Sk next st, dc in next st; working in front of dc just made, dc in skipped st; dc in next st; rep from * across; ch 3, turn.

Row 3: *Sk next st, dc in next st, dc in skipped st as before; BPdc around next dc; rep from * across; end last rep with dc in top of turning ch; ch 3, turn. 

Row 4: *Sk next st, dc in next st, dc in skipped st as before; FPdc around next BPdc; rep from * across; end last rep with dc in top of turning ch; ch 3, turn.

Rep rows 3 and 4 for patt.