--===== Create the table with columns for N and N!.
     -- This will prepopulate the values of N, as well.
 SELECT TOP 171
        N = IDENTITY(INT,0,1),
        [N!] = CAST(0 AS FLOAT)
   INTO dbo.Factorial
   FROM sys.all_columns
;
--===== Add the quintessential PK for max performance of future lookups
  ALTER TABLE dbo.Factorial
    ADD CONSTRAINT PK_Factorial 
        PRIMARY KEY CLUSTERED (N) WITH FILLFACTOR = 100
;
--===== Declare a variable that well need to keep track of the previous product.
DECLARE @Factorial FLOAT;

--===== Update the table with factorials.
 UPDATE f
    SET @Factorial = [N!] = CASE WHEN N > 0 THEN @Factorial * N ELSE 1 END
   FROM dbo.Factorial f WITH (TABLOCKX, INDEX(1))
 OPTION (MAXDOP 1)
;
--===== Show our work
 SELECT * FROM dbo.Factorial ORDER BY N;