the page actually does give these. for α := [a-z]{2,4} the page gives |α| = 475228.
however, as others have pointed out any non-trivial use of the kleene star means the result will be ∞. in this case the page will list numbers that roughly correspond to "number of strings with N applications of kleene star" in addition to infinity.
however, as others have pointed out any non-trivial use of the kleene star means the result will be ∞. in this case the page will list numbers that roughly correspond to "number of strings with N applications of kleene star" in addition to infinity.