SELECT t1.id, t2.id, t3.id
FROM my_table t1
JOIN my_table t2 ON t2.id > t1.id AND t1.distance <> t2.distance
JOIN my_table t3 ON t3.id > t2.id
WHERE ABS(t1.distance - t2.distance) = 2*ABS(t2.distance - t3.distance)