[sqlite] Primary Key

[andy]

I'm using sqlite 3.2.8

I have a table:
create table lookups
(
  id integer,
  descr varchar(80),
  codetype integer,
  primary key(id)
);

when I use:

pragma index_list(lookups);

It returns nothing.  However, if I change the id field to text instead 
of integer, then it shows:

0|sqlite_autoindex_lookups_1|1

So my question is:

when id is an integer, is there an index?  If there is, why does it not 
show?

I see in the help that:
"the column is used internally as the actual key of the B-Tree for the 
table".

So, no actual index on the table?

But if "pragma index_list(lookups);" doesnt show one, how do I know its 
there?

Thank you,

-Andy

PS:  if this duplicates, please forgive me (I tried sending from 
gmane.org the first time.