%I #28 Oct 29 2022 08:22:21
%S 20,404,6164,75917,835491
%N Number of 3-dimensional polyominoes (or polycubes) with n cells that have cavities (inclusions of empty space).
%C Even if two polycubes are mirror images of each other, they are considered different for this sequence.
%C Polycubes with less than 11 cells can't have cavities.
%C Largest enclosed volume >= A355880(n-5) for polycubes with n cells.
%H Gleb Ivanov, <a href="/A355966/a355966.py.txt">Python program for n = 11..14</a>
%H Wikipedia, <a href="https://en.wikipedia.org/wiki/Polycube">Polycube</a>
%Y Cf. A001419, A000162, A038119, A355880.
%Y Cf. A357083 (without distinguished reflections).
%K nonn,more,hard
%O 11,1
%A _Gleb Ivanov_, Jul 21 2022