User:Jnestorius/List of ordinal anomalies

Pope John the nth

..., Pope John XIX, no Pope John XX, Pope John XXI, ...

Pope Martin the nth

Pope Martin I, no Pope Martin II, no Pope Martin III, Pope Martin IV, ...

nth President of the United States

..., 21 Chester A. Arthur, 22 Grover Cleveland, 23 Benjamin Harrison, 24 Grover Cleveland again, 25 William McKinley, ...

nth Amendment of the Irish Constitution

..., 11, no 12, 13, 14, ..., 20, 21, no 22, 23, no 24, no 25, 26

Games of the nth Olympiad

..., Vth, no VIth, VIIth, ... , XIth, no XIIth, no XIIIth, XIVth, ...

First Blood / Rambo n

First Blood, Rambo: First Blood Part II, Rambo III (not Rambo II / First Blood Part III), John Rambo (this one is hardly an anomaly; when n is embarrasingly large, the producers usually drop it)

Apollo program

Apollo 1, no Apollo 2 or 3, Apollo 4, ...