Use While Loop to insert series of numbers in SQL Server Database

Refer this:

You can change the start and end index as you want.

CREATE TABLE [dbo].[TableNumbers](
	[ID] [int] IDENTITY(1,1) NOT NULL,
	[Code] [int] NULL,
 CONSTRAINT [PK_TableNumbers] PRIMARY KEY CLUSTERED 
(
	[ID] ASC
)WITH (PAD_INDEX  = OFF, STATISTICS_NORECOMPUTE  = OFF, IGNORE_DUP_KEY = OFF, ALLOW_ROW_LOCKS  = ON, ALLOW_PAGE_LOCKS  = ON) ON [PRIMARY]
) ON [PRIMARY]

GO
DECLARE @i INT
SET @i = 0
WHILE @i <= 20
BEGIN
   INSERT INTO [TableNumbers] (Code) VALUES(@i)

   SET @i = @i + 1
END

Thank You.