Die hard nx1 polyomino patterns

[Rhombic]

I have noticed, coincidentally, that nx1 linear patterns die for n=1,2,6,14,15,18,19,23,24
Apparently, it gets increasingly improbable that for n>100 this happens, because the end population tends to increase (there are local minima, but in general it tends to be higher than the previous average).

So here goes my question: are there more die hard nx1 polyomino patterns (effectively, lines)?
Alternatively, how would one design a method to prove the existence -or lack thereof- of these?

[Nathaniel]

Alternatively, how would one design a method to prove the existence -or lack thereof- of these?

All lines of sufficiently high length (about 350 cells or more) emit gliders in very predictable ways and thus won't die off completely. So you just need to check the lines with length smaller than that.