Crochet Mile a Minute Scarf

With CA, ch 240.
Rnd 1: Ch 4, in 5th ch from hook work (tr, ch 3, 2trcl, [Vst] twice) all in same ch, skip next 4 ch, [Vst in next ch, skip next 4 ch] 46 times, [Vst] 3 times in last ch – mark last 3 Vsts for corner; turn to work on opposite side of ch, skip next 4 ch, * Vst in next ch, skip next 4 ch; rep from * to end; join with a sl st in top of ch-4.
Rnd 2: Ch 1, ** [5 sc in next ch-3 sp, sc between next two 2trcl] 3 times, * 3 sc in ch-3 sp, sc between next two 2trcl; rep from * to corner Vsts ***; rep from ** around, end at ***; join with a sl st in first sc. Fasten off.
Rnd 3: With right side facing, join CB in last sc worked; (ch 4, tr, ch 3, 2trcl) all in same sc, * [skip next 2 sc, Vst in next sc] twice, [skip next sc, Vst in next sc] 3 times, [skip next 2 sc, Vst in next sc] twice; skip next 3 sc, [Vst in next sc, skip next 3 sc] 45 times **, Vst in next sc; rep from * around, end at **; join in top of ch-4.
Rnd 4: Ch 1, * 3 sc in ch-3 sp, sc between next two 2trcl; rep from * around; join.
Rnd 5: With right side facing, join CA in next sc after joining; ch 1; (sc, ch 3, sc) all in same sc – picot made, * skip next sc, picot in next sc; rep from * around; join. Fasten off. Weave in ends.

2trcl = * [yo] twice and draw up a lp in st specified, [yo and draw through 2 lps] twice; rep from * once more; yo and draw through all 3 lps on hook.
Vst = (2trcl, ch 3, 2trcl) all in same st.

Adapted from: Coats and Clarks' Mile a Minute Scarf