Here is another method .... not efficient .... not recommended ... but it does what you seem to need to do.

DECLARE @BegYr INT = 2013

DECLARE @EndYr INT = 2015

DECLARE @E INT

DECLARE @a VARCHAR(10)

DECLARE @Z VARCHAR(10)

SET @E = @BegYr

SET @Z = (SELECT SUBSTRING(CAST(@E AS VARCHAR(4)),LEN(CAST(@E AS VARCHAR(4))),LEN(CAST(@E AS VARCHAR(4)))))

WHILE @E < @EndYr

BEGIN

SET @E = @E + 1

SET @a = (SELECT '/' + SUBSTRING(CAST(@E AS VARCHAR(4)),LEN(CAST(@E AS VARCHAR(4))),LEN(CAST(@E AS VARCHAR(4)))))

SET @Z = @Z + @a

END

SELECT @Z

Result:

3/4/5

If you would/could explain why you have this requirement, some may be able to assist you with a more efficient solution.