Generate all combinations in SQL

I need to generate all combinations of size @k in a given set of size @n. Can someone please review the following SQL and determine first if the following logic is returning the expected results, and second if is there a better way?

/*CREATE FUNCTION dbo.Factorial ( @x int ) 
RETURNS int 
AS
BEGIN
    DECLARE @value int

    IF @x <= 1
        SET @value = 1
    ELSE
        SET @value = @x * dbo.Factorial( @x - 1 )

    RETURN @value
END
GO*/
SET NOCOUNT ON;
DECLARE @k int = 5, @n int;
DECLARE @set table ( [value] varchar(24) );
DECLARE @com table ( [index] int );

INSERT @set VALUES ('1'),('2'),('3'),('4'),('5'),('6');

SELECT @n = COUNT(*) FROM @set;

DECLARE @combinations int = dbo.Factorial(@n) / (dbo.Factorial(@k) * dbo.Factorial(@n - @k));

PRINT CAST(@combinations as varchar(max)) + ' combinations';

DECLARE @index int = 1;

WHILE @index <= @combinations
BEGIN
    INSERT @com VALUES (@index)
    SET @index = @index + 1
END;

WITH [set] as (
    SELECT 
        [value], 
        ROW_NUMBER() OVER ( ORDER BY [value] ) as [index]
    FROM @set
)
SELECT 
    [values].[value], 
    [index].[index] as [combination]
FROM [set] [values]
CROSS JOIN @com [index]
WHERE ([index].[index] + [values].[index] - 1) % (@n) BETWEEN 1 AND @k
ORDER BY
    [index].[index];