30P4H2V0.4 is a spaceship. It is one of the relatively few spaceships that can be constructed by gliders, though the best available still-life constellation seed for the final construction stage (found by Tanner Jacobi on 10 September 2015) is unusually complex. It maintains a singly skewed D2_+2 symmetry — an extremely unusual symmetry both in Life and in 2D square-grid CAs in general — in three out of its four phases.
Improvements to the synthesis have since been found.
- 30P4H2V0.4 at Heinrich Koenig's Game of Life Object Catalogs