SQL Server 2017

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CREATE TABLE stats (
  account_id integer NOT NULL PRIMARY KEY,
  order_count char(128)
);

INSERT INTO stats
SELECT 1, 9
UNION
SELECT 2, 3;
2 rows affected

with gen (account_id, n, order_count) as (
select account_id, 1, order_count from stats
union all
select account_id, n+1, order_count
from gen where n < order_count
)
select n-2 as x, n as y, account_id, n
from gen
where n % 3 = 0
order by account_id, n;


x
y
account_id
n


1
3
1
3

4
6
1
6

7
9
1
9

1
3
2
3