128P10.2 is an unnamed period-10 quasi-shuttleoscillator.[1] It was found by Nicolay Beluchenko on March 26, 2009.[2] It is not considered a true shuttle because the active region does not flip halfway through the oscillator's period.
This oscillator first appeared semi-naturally in April 2016, in a symmetricsoup submitted to Catagolue.[3] On October 27, 2020, a glider synthesis of this oscillator (or, more specifically, a slight variant) was completed, following intermittent efforts by various users dating back to July.[4] Since then, about 1 in 5.5 billion eightfold symmetric soups with odd symmetry (D8_1) form a 128P10.2 with the blocks in one of two possible positions.
