If I am not mistaken #151 is Mew, which is only obtainable by "migrating" from Pokemon Fire Red or Leaf Green. It's only available in Fire Red or Leaf Green through a special Nintendo Event.
= 152
151 manapy 152 rotom
rotom
Pokemon 152 is Chickoreta
Rotom.
Sinnoh Dex #152 -- Rotom National Dex #152 -- Chikorita
rotom
Rotom
Picachu
In the sinnoh pokedex rotom is number 152 but in the national pokedex rotom is number 479 and chickorita is number 152
Pokemon Platinum has two different Pokedexes: the Sinnoh dex and the National Pokedex. In the Sinnoh dex, #152 is Rotom. In the National Pokedex, it's Chikorita.
Rotom