Perhaps input_number with range of 1-4 and the template sensor that would translate these values to what you expect. E.g.
1 → 4
2 → 5
3 → 6
4 → 10
Alternatively small automation that would call input_select.set_value depending on what state input_number value got set to. Not the most elegant solutions, but wouyld do the trick of using slider and to ‘skip unwanted’ values.