The phrase "a sequence in which they" is correct and usable in written English.
It can be used when describing a specific order or arrangement of elements or events involving a group of people or things.
Example: "The study analyzed a sequence in which they completed the tasks to determine efficiency."
Alternatives: "an order in which they" or "a series in which they".
In the introduction of "Lucky Charms" the dancers perform a sequence in which they switch between stretching formally up and out, then swinging low and casually.
Also, they were occasionally losing the tempo during some of the zanier stage actions instigated by the director, Jonathan Kent — notably, a sequence in which they donned pink-and-white bunny suits and simulated a variety of sex acts.
There's also a sequence in which they and their friends sit at lunch shooting the breeze, and you realise exactly what Before Midnight is – a philosophical symposium in the Ancient Greek manner.
Together, they have odd-couple chemistry, not least in a sequence in which they tie a clothes line between their horses to dry their sodden duds, a routine that wouldn't have looked out of place in Laurel and Hardy's Way Out West.
Since Jonny Wilkinson dropped the goal in extra-time in Sydney in 2003 to pip Australia for the Webb Ellis Trophy, England have lost 12 of their 23 Test matches, a sequence in which they have yet to defeat France or Ireland in the Six Nations.
Tuesday's defeat at Manchester City stretched their winless run to eight games, a sequence in which they had scored only three goals and picked up two points.
There is a great sequence in which they attend a church service, blandly complaisant, not making a fuss, not standing out, biding their time.
Underlying this hypothesis is the fundamental principle of Farr's Law: epidemics follow a natural sequence in which they spread and subside in a pattern that approximates a symmetric curve (Bregman and Langmuir [1990]).
Then the Cubs began a torturous sequence in which they booted two double-play balls in a row.
Participants then received the ILT instructions and completed a training sequence in which they were presented with all three phases of the ILT using different fruits than in the main experiment.
This results in an affecting sequence in which they're drawn into the life of this poor community.
