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 A368029 #19 Dec 10 2023 11:42:55 %S A368029 1,1,1,4,5,18,33,70,110,246,526,1144,2366,4689,8597,15168,26367,46696, %T A368029 82428,142991,240609,393640,627305,975760,1474671,2164515,3084956, %U A368029 4282222,5810980,7776373,10351373,13815334,18556147,25107905 %N A368029 Number of free midpoint-free polycubes of size n, identifying rotations and reflections. %C A368029 Midpoint-free means that no three cubes are in positions (x,y,z), (x+dx,y+dx,z+dz), and (x+2*dx,y+2*dx,z+2*dz). %e A368029 The polycubes for n <= 5 are: %e A368029 n=1: %e A368029 0,0,0 %e A368029 n=2: %e A368029 0,0,0; 0,0,1 %e A368029 n=3: %e A368029 0,0,0; 0,0,1; 0,1,0 %e A368029 n=4: %e A368029 0,0,0; 0,0,1; 0,1,0; 0,1,1 %e A368029 0,0,0; 0,0,1; 0,1,0; 1,0,0 %e A368029 0,0,0; 0,0,1; 0,1,0; 1,0,1 %e A368029 0,0,0; 0,0,1; 0,1,1; 0,1,2 %e A368029 n=5: %e A368029 0,0,0; 0,0,1; 0,1,0; 0,1,1; 1,0,0 %e A368029 0,0,0; 0,0,1; 0,1,0; 1,0,1; 1,0,2 %e A368029 0,0,0; 0,0,1; 0,1,0; 1,0,1; 1,1,0 %e A368029 0,0,0; 0,0,1; 0,1,1; 0,1,2; 1,0,1 %e A368029 0,0,0; 0,0,1; 0,1,1; 1,1,1; 1,1,2 %Y A368029 Cf. A368030, A363203, A363204, A363207. %K A368029 nonn,more %O A368029 1,4 %A A368029 _Joerg Arndt_ , Dec 08 2023