Cannot see any reason for scanning the table to produce the week numbers when it can be done more efficiently without it.
😎

Here is a far better method with only two constant scans and no sort operator.


USE TEEST;
GO
SET NOCOUNT ON;

;WITH T(N) AS (SELECT X.N FROM (VALUES (0),(0),(0),(0),(0),(0),(0),(0)) X(N))
, NUMS(N) AS (SELECT TOP (52) ROW_NUMBER() OVER (ORDER BY @@VERSION) AS N
     FROM T T1,T T2)
SELECT
  NM.N AS WEEK_NUM
FROM  NUMS  NM
ORDER BY NM.N;