How to create a dynamic list?

I 'd like create a type like a dynamic list.

I've tried

CREATE TYPE liste
(
 INPUT = array_in,
 OUTPUT = array_out,
 INTERNALLENGTH = VARIABLE,
 ELEMENT = int
);

CREATE TABLE xxx
(
 num  int,
 nom  varchar(10),
 nb     liste,
 PRIMARY KEY(num)
);

This instruction give an error :

INSERT INTO xxx
VALUES(1,'aaa',(10,20,30));

ERROR:  parser: parse error at or near ")"

Could someone tell me how do I have to do?
Thanks

Renaud THONNART