I was deleting thousands of records each time with \gexec, then ...
This one works
select format('delete from table where ID = any(%L::integer[]);', array_agg(ID)), (ord-1)/10000 from ( select * from generate_series(15e2,65e5) with ordinality) x(ID, ord) group by 2 order by 2;
But it's easier to write in exponential notation, so I changed this (ord-1)/10000 to (ord-1)/1e4. Using this way exponential notation is just ignored.