Fast answer: use the R-pentomino
A user asking for a 3x3 methuselah usually wants a concrete pattern, not a category definition. The R-pentomino is the clean answer because its five-cell seed fits inside a 3 x 3 bounding box and then takes 1,103 generations to stabilize.
That makes it a good first live experiment. You can inspect the starting cells by hand, step through the first few generations, and then speed up once the reaction spreads beyond the original box.
Compare quickly
3x3 methuselah candidates
The search term is narrow, but nearby patterns help explain what is and is not a 3x3 methuselah.
| Pattern | Fits 3 x 3? | Key number | Search promise | Why run it |
|---|---|---|---|---|
| R-pentomino | Yes, five cells in 3 x 3 | 1,103 generations | Standard 3x3 methuselah answer | Step it slowly from generation 0 |
| Acorn | No, 7 x 3 | 5,206 generations | Longer small methuselah | Compare a wider seed with a longer transient |
| Diehard | No, 8 x 3 | 130 generations | Ends in extinction | See a long-lived pattern disappear |
| Edna | No, 20 x 20 | 31,192 generations | Large methuselah benchmark | Use after the small-seed examples |
Start with the R-pentomino
The R-pentomino begins with only five live cells inside a 3 x 3 bounding box, which makes it the clearest small methuselah to inspect by hand.
That tiny seed is famous because it does not settle quickly. It takes 1,103 generations to stabilize, ending with a final census of 116 cells and 6 escaping gliders.
Compare it with Acorn and Diehard
Acorn is another classic small methuselah, but it is not 3 x 3. It starts with seven cells in a 7 x 3 bounding box, lasts 5,206 generations, and stabilizes with 633 cells.
Diehard is useful because it teaches the opposite outcome. It starts with seven cells in an 8 x 3 bounding box, stays active for 130 generations, and then completely vanishes.
Edna shows the extreme end
Edna is not a beginner-sized 3x3 pattern. It starts with 149 cells in a 20 x 20 bounding box and lasts 31,192 generations.
Including Edna beside R-pentomino, Acorn, and Diehard helps separate two ideas: a methuselah can be small enough to inspect by hand, or large enough to act as an automated enumeration benchmark.
How to use the live pages
Start with the R-pentomino page and run the pattern slowly for the first few ticks. Then switch to Acorn for a long expansion, Diehard for extinction, and Edna for a much larger transient.
Use the pattern library search for terms such as 3x3 methuselah, R-pentomino, Acorn, Die Hard, Edna, 31192, and Gosper gun when you want to jump directly to a runnable pattern.
Working takeaway
Use R-pentomino as the compact 3 x 3 example, then use Acorn, Diehard, and Edna to show how methuselah behavior changes with seed size and outcome.
Fast answers
Common search questions
Which Conway Life pattern is the 3x3 methuselah?
The R-pentomino is the clearest 3 x 3 methuselah example on this site. It has five live cells, runs for 1,103 generations, and ends with 116 live cells including 6 gliders.
Is Diehard the same as the 3x3 methuselah?
No. Diehard is another small methuselah-like pattern to compare, but its seed is 8 x 3 and it eventually disappears after 130 generations.
What should I watch when running the R-pentomino?
Watch the first expansion slowly. The useful moment is seeing how five cells stop looking like a tiny seed and start producing a much wider field of debris.