An uninterrupted sequence can be about as simple as a rhythm can get. All rhythms involve a sequence. Repeating shapes can create a pattern that – depending on which kind of sequence it assumes – may result in a sense of movement, generally referred to as rhythm.
An uninterrupted sequence is as simple as it gets. Depending on the nature of what’s being repeated, movement can result as well. It’s hard to find movement in static patterns, that’s why not all patterns have rhythm. Patterns with even the slightest degree of variation can still produce a rhythm.