This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.
%I A355966 #28 Oct 29 2022 08:22:21 %S A355966 20,404,6164,75917,835491 %N A355966 Number of 3-dimensional polyominoes (or polycubes) with n cells that have cavities (inclusions of empty space). %C A355966 Even if two polycubes are mirror images of each other, they are considered different for this sequence. %C A355966 Polycubes with less than 11 cells can't have cavities. %C A355966 Largest enclosed volume >= A355880(n-5) for polycubes with n cells. %H A355966 Gleb Ivanov, <a href="/A355966/a355966.py.txt">Python program for n = 11..14</a> %H A355966 Wikipedia, <a href="https://en.wikipedia.org/wiki/Polycube">Polycube</a> %Y A355966 Cf. A001419, A000162, A038119, A355880. %Y A355966 Cf. A357083 (without distinguished reflections). %K A355966 nonn,more,hard %O A355966 11,1 %A A355966 _Gleb Ivanov_, Jul 21 2022