Agréger bitwise-OR dans une sous-requête

WITH    Bits
          AS ( SELECT   1 AS BitMask
               UNION ALL
               SELECT   2
               UNION ALL
               SELECT   4
               UNION ALL
               SELECT   8
               UNION ALL
               SELECT   16
             )
    SELECT  SUM(DISTINCT BitMask)
    FROM    ( SELECT    1 AS n
              UNION ALL
              SELECT    2
              UNION ALL
              SELECT    3
              UNION ALL
              SELECT    4
              UNION ALL
              SELECT    5
              UNION ALL
              SELECT    6
            ) AS t
            JOIN Bits ON t.n & Bits.BitMask > 0