An excellent seed that will spawn you next to the mansion in the dark mushroom forest. You can immediately explore a huge house at coordinates 320 ~ 400, but inside it you can meet hostile skeletons and enchanters. If you delay the visit to the mansion for a long time, then it may burn out, since it is located next to the lava source.
How to use Mansion in the Dark Forest seed
Start the Singleplayer mode
Select ‘Create New World’
Then click on ‘More World Options…’
In the ‘Seed for the World generation’ field, enter 1483524782