List of Pokémon by index number (GBA)
From Bulbapedia, the community-driven Pokémon encyclopedia.
In each Pokémon game of Generation III, all Pokémon have an unseen index number used to identify them in the game's ROM. The majority of them are in their National Dex order, in fact, all Pokémon from 001 to 251, inclusive, are in the same position as they are in the National Dex.
