345/3456/6 is a so far unnamed rule which has a natural still life, period 2 oscillator, and 12c/24 Spaceship. It is dominated by interacting linear growths.
Patterns
The following is a common 12c/24 spaceship. It is quite sparky:
x=7, y = 8, rule = 345/3456/6
.2A$B2AB$CAC2A$DE3A$2.EC2A$.EC3A$3.DB2A$2.EC2A!
The rule also has a common backrake:
x=8, y = 8, rule = 345/3456/6
.BC$BDAEA$CA.3A$.B2AB2A$2.A.DBA$3.DB3A$4.EC2A$4.DB2A!
There is also a puffer, occurring with appreciable frequency:
x=17, y = 15, rule = 345/3456/6
13.3A$11.5A$9.3ABACB$7.3ABADAED$6.2ABADA.2A$5.2ABDA.CABA$4.BE2A.CBEAB
AD$3.C2A.2AEDAB2EBC$2.2B2D3A2.CD.DCD$.AC2D3A3.E3.E$.2ADC.B2A$2ABD.A2B
A$.3A2.3A$2.AE2AE$4.2A!