A sequencer uses scenes in a sequential order.
When you select a sequencer, the following screen is displayed.
Choose the first scene for choice 1. The 2nd will follow automatically as this is the next scene in the sequence you programmed. This means that the first press will activate the scene in position 1, and the next press will activate the scene in position 2. It is a looping process.
With the option "Number" on the right side you can select the number of scenes for this scene. Choose the first, the rest will follow the scene set as primary, based on the order in which these scenes were created. When this sequencer is assigned to a key, each press of the key will I/O the following scene.
When pressed for a long time, the first scene is always activated.