x = 21, y = 15, rule = B3678/S34678
10bo$8b5o$5b11o$6b9o$3b15o$4b13o$bb17o$21o$bb17o$4b13o$3b15o$6b9o$5b
11o$8b5o$10bo!
A period 38 oscillator.
This can be formed by impacting two nova explosions onto a nova core.
David I. Bell, October 1997

