Research for a set of particular primitive Pythagorean triples

The set of terms of an infinite sequence expressed by a recurrence relation is equal to the set of maximum numbers of all primitive Pythagorean triples such that the difference between the two non-maximum numbers is 1, which Cimmino showed. By reference to Cimmino’s researches, we show a recurrence relation for the case where the difference between the two non-maximum numbers is not 1, but 7.