Finding missing sequence no.

Hi,

Can any one help me in finding missing no.s in a column
USING SINGLE SQL .

For eg column a contains 1,3,6,10

I want the answer as 2,4,5,7,8,9

You can use either of the 2 sql's

1)select nvl(max(a.t),0) + 1 gapfrom,b.t-1 gapto
from temp a ,temp b
where a.t(+) < b.t
group by b.t having nvl(max(a.t),0) < b.t -1;

2) select a.t +1,b.t -1 from temp a,temp b where
a.t +1 not in(select t from temp) and
b.t=(select min(t) from temp where t > a.t)

Cheers

Here is another simple solution.
select rownum from tab
where rownum <= ( select max(x) from your_table )
minus
select x from your_table