I don't actually understand why you would need to know how to do that to get a job, it's just weird I've been coding for 15 years and I never used that sequence for anything... If someone asks me to do a Fibonacci sequence or whatever it's called when I apply for my next job, I'll just say thanks, but I don't want to work here if this is the kind of crap you are gonna pull...
/slams door.
They can ask me to reverse engineer an app or show them I know how to use the stl library or something you actually have to use or be able to do, but these kind of tests only produce a bunch of likeminded drones and I guess that's what some companies wants, but I'd rather be with a team that values thinking outside the box and individual talent.