1767. Find the Subtasks That Did Not Execute.ms sql server

WITH temp AS (
SELECT task_id,1 as subtask_id,subtasks_count from Tasks
union all
select task_id,(subtask_id +1) as subtask_id,subtasks_count from temp
where subtask_id <subtasks_count
)
select task_id,subtask_id from temp
except
select task_id,subtask_id from executed