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 A384109 #13 May 24 2025 05:57:17 %S A384109 1,2,2,5,14,41,135,461,1610,5564,18769,59513,173692,448720,993666, %T A384109 1820321,2700927,3225519,3146565,2555112,1761447,1041034,531851, %U A384109 234072,88977,28779,7997,1837,378,62,12,2,1 %N A384109 Number of connected components of n faces of the truncated icosahedron up to the 120 rotations and reflections of the truncated icosahedron. %C A384109 Two faces are connected if they share an edge. %C A384109 These are "free" polyforms because both rotations and reflections are allowed. %C A384109 The truncated icosahedron is the polyhedral dual of the pentakis dodecahedron. %H A384109 Peter Kagey, <a href="/A384109/a384109.pdf">Illustration of a(1)-a(3)</a>. %H A384109 Wikipedia, <a href="https://en.wikipedia.org/wiki/Truncated_icosahedron">Truncated icosahedron</a> %e A384109 a(1) = 2 because the truncated dodecahedron is not face transitive, but has two distinct orbits of faces: (1) pentagons and (2) hexagons. %Y A384109 Cf. A384067 (cuboctahedron), A384068 (truncated cube), A384069 (truncated octahedron), A384070 (rhombicuboctahedron), A384071 (cuboctahedron), A384072 (snub cube), A384104 (truncated tetrahedron), A384107 (icosidodecahedron), A384108 (truncated dodecahedron), A384109 (truncated icosahedron), A384110 (rhombicosidodecahedron), A384111 (truncated icosidodecahedron), A384112 (snub dodecahedron). %K A384109 nonn,fini,full %O A384109 0,2 %A A384109 _Peter Kagey_, May 20 2025 %E A384109 a(11)-a(32) from _Bert Dobbelaere_, May 24 2025