WITH CTE (rowNum,Value,Level) AS
(
        SELECT ROW_NUMBER() OVER (ORDER BY ID DESC) as rowNum,
                   Value
                   0 as Level
        FROM    Mytable
        WHERE  ID = (SELECT MIN(ID) FROM Mytable)
        UNION ALL
        SELECT ROW_NUMBER() OVER (ORDER BY ID DESC) as rowNum,
                   Value
                   Level + 1
        FROM    Mytable a INNER JOIN CTE b ON b.rowNum <= a.rowNum + 1 --a.rowNum are not allowed here       
)

SELECT rowNum, SUM(Value)
FROM CTE
GROUP BY LEVEL, rowNum

DECLARE @factorial VARCHAR(255) 

SET @factorial = '' 

CREATE TABLE #temp 
  ( 
     id    INT, 
     value VARCHAR(255) 
  ) 

INSERT INTO #temp 
            (id, 
             value) 
SELECT 1, 
       '19' 
UNION 
SELECT 2, 
       '90' 
UNION 
SELECT 3, 
       '20' 
UNION 
SELECT 4, 
       '8' 
UNION 
SELECT 5, 
       '9' 

UPDATE #temp 
SET    @factorial = value = ( CASE 
                                WHEN @factorial <> '' THEN @factorial + ' + ' 
                                ELSE @factorial 
                              END ) + value 

SELECT * 
FROM   #temp 

DROP TABLE #temp  

SELECT * INTO #MyTable
FROM (VALUES(1,19), (2,90), (3,20), (4,8), (5, 9)) AS M(ID, VALUE)

-- triangular join
select ID
    , VALUE
    , (
        SELECT SUM(VALUE) 
        FROM #MyTable b 
        WHERE b.ID <= a.ID
    ) AS RUNNING_TOTAL
FROM #MyTable a

-- quirky update
ALTER TABLE #MyTable ADD CONSTRAINT mt_pk PRIMARY KEY (ID)
ALTER TABLE #MyTable ADD RUNNING_TOTAL INT
ALTER TABLE #MyTable ADD RUNNING_CALC VARCHAR(100)

DECLARE @runningTotal int = 0
DECLARE @runningCalc varchar(100) = null

UPDATE #MyTable
SET @runningTotal = RUNNING_TOTAL = @runningTotal + VALUE
	,@runningCalc = RUNNING_CALC = isnull(@runningCalc + ' + ','') + CAST(VALUE AS VARCHAR(10))

SELECT * FROM #MyTable

DROP TABLE #MyTable

CREATE TABLE #temp 
  ( 
     id    INT, 
     value NVARCHAR(255) 
  ) 

INSERT INTO #temp (id,value) SELECT 1, '19' 
INSERT INTO #temp (id,value) SELECT 2, '90' 
INSERT INTO #temp (id,value) SELECT 3, '20' 
INSERT INTO #temp (id,value) SELECT 4,  '8' 
INSERT INTO #temp (id,value) SELECT 5,  '9' 
       
with cte 
as (select id, value from #temp where id =1

	union all 
	select t.id, convert (nvarchar(255),c.value+'+'+t.value)
	from #temp t inner join cte	c on c.id= (t.id-1))
	select * from cte

/*ID | Value
---------
1 | 19
2 | 90
3 | 20
4 | 8
5 | 9
*/


DECLARE @valuestab TABLE (ID INT,VALUE INT)

INSERT INTO @valuestab
        ( ID, VALUE )
VALUES  ( 1,19
          ),(2,90),(3,20),(4,8),(5,9);

 WITH CTE (ID,Value) AS
(
        SELECT ID,
                   Value
        FROM    @valuestab
        UNION ALL
        SELECT a.id,
                   a.Value + b.Value
        FROM    @valuestab a 
        INNER JOIN CTE b 
			ON b.ID +1 = a.ID       
)

SELECT ID, MAX(Value) AS Value
FROM CTE
GROUP BY ID

 WITH CTE (ID,Value) AS
(
        SELECT ID,
                   Value
        FROM    @valuestab
        WHERE  ID = (SELECT MIN(ID) FROM @valuestab) --I guess you forget this line
        UNION ALL