DECLARE FUNCTION catalan (n as INTEGER) AS SINGLE

REDIM SHARED results(0) AS SINGLE

FOR x% = 1 TO 15
    PRINT x%, catalan (x%)
NEXT

FUNCTION catalan (n as INTEGER) AS SINGLE
    IF UBOUND(results) < n THEN REDIM PRESERVE results(n)

    IF 0 = n THEN
      results(0) = 1
    ELSE
      results(n) = ((2 * ((2 * n) - 1)) / (n + 1)) * catalan(n - 1)
    END IF
    catalan = results(n)
END FUNCTION