Bulbapedia Oak's first name and age ?

[Walven]

Hi !

On page Prof. Oak (Professor Oak - Bulbapedia, the community-driven Pokémon encyclopedia), it is stated that his first name is Samuel and he is 47 years old.

However, I have two questions:

- His first name it is not exclusive to the anime?
- Where his age was mentioned so precisely?

Thanks c:

 

[ShadowZone1996]

He is 50 years old in GSC/HGSS therefore he must be 47 in the games before since there's three years in between

 

[Walven]

Is it said he's 50 in HGSS? When?