A $n$-polyplet is a collection of $n$ cells on a grid which are orthogonally or diagonally connected.
The number of $n$-polyplets is given by the OEIS sequence A030222: $1, 2, 5, 22, 94, 524, 3031, \dots$
See below the five $3$-polyplets:
A polyplet will be called $1$-step vanishing on Conway's game of life, if every cell dies after one step.
We observed that for $n\le 4$, a $n$-polyplet is $1$-step vanishing iff $n \le 2$.
We found $1$-step vanishing polyplets with $n=9, 12$, see below:
Question: Is there an other $1$-step vanishing $n$-polyplet with $n \le 12$?
If yes, what are they? (note that there are exactly $37963911$ $n$-polyplets with $n \le 12$).
We can build infinitely many $1$-step vanishing polyplets with such pattern, see below with $n=142$:
Bonus question: Are there $1$-step vanishing polyplets of an other kind?