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 A363203 #9 May 21 2023 12:56:39 %S A363203 1,1,1,2,4,9,20,51,128,338,882,2350,6238,16693,44561,119339,319104, %T A363203 854420,2285357 %N A363203 Number of free linear polycubes of size n, identifying rotations and reflections and avoiding neighbors at [0,0,+-2], [0,+-2,0], and [+-2,0,0]. %C A363203 Linear polycubes have two end points with one neighbor, the remaining cubes all have two neighbors. %C A363203 When a cube [x,y,z] is in the polycube then neither of the six cubes [x+-2,y,z], [x,y+-2,z], [x,y,z+-2] can be in the polycube. For example, no three cubes can be in a row. %Y A363203 Cf. A363204 (linear and avoiding at [+-1,+-1,+-1]). %K A363203 nonn,more %O A363203 1,4 %A A363203 _Joerg Arndt_ and _Márk Péter Légrádi_, May 21 2023