210.11 (2) Laundry Branch Circuits. In addition to the number of branch circuits required by other parts of this section, at least one additional 20-ampere branch circuit shall be provided to supply the laundry receptacle outlet(s) required by 210.52(F). This circuit shall have no other outlets.
This means that the least amount that can be installed is one but if one chooses they can install more
210.23 (A) 15- and 20-Ampere Branch Circuits. A 15- or 20- ampere branch circuit shall be permitted to supply lighting units or other utilization equipment, or a combination of both, and shall comply with 210.23(A)(1) and (A)(2).
Exception: The small-appliance branch circuits, laundry branch circuits, and bathroom branch circuits required in a dwelling unit(s) by 210.11(C)(1), (C)(2), and (C)(3) shall supply only the receptacle outlets specified in that section.
210.23 allows a 20 ampere circuit to supply equipment and lighting outlets but the exception is very clear that laundry circuits (meaning more than one) shall have no other outlets.
220.52 (B) Laundry Circuit Load. A load of not less than 1500 volt-amperes shall be included for each 2-wire laundry branch circuit installed as covered by 210.11(C)(2). This load shall be permitted to be included with the general lighting load and subjected to the demand factors provided in Table 220.42.
Here the word ?each? is implying more than one.
Taking the NEC as a whole instead of blindly looking at one sentence one can clearly see that more than one laundry circuit can be installed and if more than one is installed then each has to follow the same rules that only one would be required to follow.