Crystal Growth 1

The rule

In Softology's notation 0-6/1,3/2/N. The N means the von Neumann neighbourhood: a cell looks only at the 6 cells that share a face with it. A live cell survives with 0 to 6 live neighbours, which is always, so no cell ever dies. A dead cell is born with exactly 1 or 3 live neighbours.

What it does

It starts from a single live cell in the middle of the box, and there is no randomness anywhere, so every run is the same. The population for the first seven generations is 7, 13, 43, 49, 79, 133 and 259 in any box big enough. Then births stop: in a 15×15×15 box at generation 8, with 307 cells, and in a 30×30×30 box at generation 19, with 2,389. From then on nothing changes. The start and the rule are both symmetric, so the crystal is too.

Crystal Growth 2 has the same births but survives only with 1 or 2 neighbours and has 5 states: its crystal's inside never stops flickering.

Grow the crystal →

How the rule works

• Each cell has 6 neighbours: the cells that share one of its faces (the von Neumann neighbourhood).
• An empty cell comes alive when 1 or 3 of its neighbours are alive.
• A live cell never dies, whatever its neighbours do.

Picking it in the app restarts the world from a single live cell in the centre of the box.

Notation

B lists the neighbour counts at which an empty cell is born, S those at which a live cell survives, and C the number of states. How to read a rule

More of Softology's rules

• 445 B4/S4/C5
• Amoeba B5-7,12-13,15/S9-26/C5
• Architecture B3/S4-6
• Builder 1 B4,6,8-9/S2,6,9/C10
• Builder 2 B1/S5-7
• Clouds 1 B13-14,17-19/S13-26
• Clouds 2 B13-14/S12-26
• Coral B6-7,9,12/S5-8/C4
• Crystal Growth 2 B1,3/S1-2/C5
• Pyroclastic B6-8/S4-7/C10
• Spiky Growth B13,17,20-26/S0-3,7-9,11-13,18,21-22,24,26/C4
• 3D Brain B4/S

All 30 rules · From 2D to 3D: why Conway's rule needs changing in 3D