Minecraft wiki entry for Seed_(level_generation), associated text: The Java Edition demo world seed can be played in the full version by entering North Carolina in the seed input.
The PC Gamer demo world seed can be played in the appropiate era by entering glacier, all lowercase unlike the famous seed where the G is capitalized, in the seed input.
The seed for each title screen panorama are as follows:
The panorama used between Beta 1.8 Pre-release and 18w22c is either 2151901553968352745 or 8091867987493326313,[12] generated between Beta 1.6.6 and Beta 1.7.
The panorama used for Java Edition 1.13 is 1458140401, which is the seed resulting from typing 18w22a in as a seed, generated in snapshot 18w22a.
Java Edition 1.14 is 2802867088795589976, taken in 18w48a.
Java Edition 1.15 is -4404205509303106230, taken in 19w40a.
Java Edition 1.16 is 6006096527635909600, taken in 20w13a.
Java Edition 1.18 is 2151901553968352745, taken in 21w40a.
The seed for the original pack.png file is 3257840388504953787, generated in Alpha v1.2.2.[13] It can also be generated between Alpha v1.2.0 and Beta 1.7.3 with minor population differences.
The seed for the Skull on Fire painting is either -6984854390176336655 or -1044887956651363087, generated in Alpha v1.1.2_01 or prior.[14]
The seed used for the original Herobrine doctored screenshot is 478868574082066804, generated in Alpha v1.0.16_02.