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 A385275 #11 Jun 26 2025 01:16:48 %S A385275 1,1,3,6,26,92,441,2025,10141,51131,264938,1387761,7364492,39433242, %T A385275 212959457,1158325878,6341136682,34911146404 %N A385275 Number of face-connected components of irregular pyramidal cells in the square quarter pyramidille up to translation, rotation, and reflection of the honeycomb. %C A385275 These are "free polyforms" because they are counted up to rotation and reflection. %C A385275 The dual of the square quarter pyramidille is the runcitruncated cubic honeycomb. %C A385275 Each irregular pyramidal cell is similar to the convex hull of (0,0,0), (0,0,1), (0,1,0), (0,1,1), and (1,1,1). %H A385275 Peter Kagey, <a href="/A385275/a385275.gif">Animation illustrating the a(4)=26 connected 4-cell components</a>. %H A385275 Wikipedia, <a href="https://en.wikipedia.org/wiki/Architectonic_and_catoptric_tessellation">Architectonic and catoptric tessellation</a> %Y A385275 Cf. A038119 (cubic), A038173 (rhombic dodecahedral), A038181 (truncated octahedral), A343909 (tetrahedral-octahedral), A365654 (square bipyramidal), A384254 (rectified cubic), A384274 (quarter cubic), A384754 (omnitruncated cubic), A385024 (tetragonal disphenoidal), A385025 (gyrobifastigium), A385026 (hexagonal prismatic), A385027 (triakis truncated tetrahedral), A385267 (half pyramidille), A385268 (oblate cubille), A385269 (quarter cubille), A385270 (elongated dodecahedral), A385271 (hexakis cubic), A385272 (phyllic disphenoidal), A385273 (quarter oblate octahedrille), A385274 (rhombic pyramidal), A385275 (square quarter pyramidille), A385276 (trapezo-rhombic dodecahedral), A385277 (triangular prismatic). %K A385275 nonn,hard,more %O A385275 0,3 %A A385275 _Peter Kagey_ and _Bert Dobbelaere_, Jun 25 2025