if you just want to concatenate the values from a given table you can try this :
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 ctec on c.id= (t.id-1))
select * from cte
if you want the sums returned. you must only change the data type of the value column and remove the +'+'+