A CTE could also be used to generate a tally table in memory. This can come in handy if you don't have access to create a table or wish to create a table for short-term use.

WITH Tally

AS

(

SELECT

TOP 20000

ROW_NUMBER() OVER (ORDER BY SC1.name) AS N

FROM

master.dbo.syscolumns AS SC1

CROSS JOIN master.dbo.syscolumns AS SC2

)