Answered earlier, I think, but yes, in both senses of "sequential." I don't know which you mean.
Sequential means gears selected in order, no direct selection of non-adjacent ratios. It does not mean push-button, no clutch to work. Motorcycles are exclusively sequential these days. They are manually operated, with the rider working the clutch and the shifter.
The previous use of "sequential" (which actually described a semi-automatic) also has a clutch, just an automatically controlled one. Whack the paddles and all the gizmos go to work to operate the clutch and shift the gears, and it disengages the clutch automatically when you stop.
Lots of things to worry about if you have one of those. It's bad enough on a manual system when hydraulics go out, the throwout bearing dies, whatever. If you have no hydraulics on a semi-auto, you're parked. It is possible to get a standard manual, whether sequential or H-pattern, to the shop without a working clutch if you have to. With a semi-auto you'll be getting towed.
Semi-auto has even entered the motorcycle world. If you're interested, check out the Yamaha FJR1300 AE (available 2006-2010) or the current Honda VFR 1200. The semi-auto hardware was an option on both bikes.