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 A229916 #18 Jun 02 2025 08:39:32 %S A229916 1,4,10,25,55,109,211,371,651,1092,1767,2775,4383,6666,9990,14806, %T A229916 21695,31265,44852,63365,89132,124250,171560,235140,321661,435670, %U A229916 587219,787663,1051669,1396309,1848190,2432288,3192615,4174278,5435945,7054030,9134731,11779666,15152584,19436993,24867486 %N A229916 Numbers of pyramid polycubes of a given volume in dimension 4. %C A229916 A (d+1)-pyramid polycube is a (d+1)-polycube obtained by gluing together horizontal (d+1)-plateaux (parallelepipeds of height 1) in such a way that the cell with coordinates (0,0,...,0) belongs to the first plateau and each cell with coordinates (0,n_1,...,n_d) belonging to the first plateau is such that n_1 , ... , n_d >= 0. %C A229916 If the cell with coordinates (n_0,n_1,...,n_d) belongs to the (n_0+1)-st plateau (n_0>0), then the cell with coordinates (n_0-1, n_1, ... ,n_d) belongs to the n_0-th plateau. %Y A229916 Cf. A229914, A227926. %K A229916 nonn %O A229916 1,2 %A A229916 _Matthieu Deneufchâtel_, Oct 03 2013