Beluchenko's p51 (or 112P51) is a period-51 oscillator that was discovered by Nicolay Beluchenko on February 17, 2009. It was the first non-trivial period 51 oscillator to be found, all previously known period 51 oscillators being made up of disjoint period 3 and period 17 oscillators. It can be extended diagonally by making copies of itself share two blocks as shown below.
A 76-glider synthesis of this oscillator was found by Jason Summers and Matthias Merzenich in April 2010. This was improved to 43 gliders by Chris Cain on January 5, 2020.
An extension of this oscillatorRLE: here