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 A214591 #10 Aug 21 2025 10:01:20 %S A214591 5,13,157,10177,3330677,5495329427,43988453613377,1673440688496376877, %T A214591 301618636251020715984377,258456549967842122873898234377, %U A214591 1057468726916674176186809546298140627 %N A214591 Number of nXnXn triangular 0..4 arrays with every horizontal row having the same average value. %H A214591 R. H. Hardin, <a href="/A214591/b214591.txt">Table of n, a(n) for n = 1..54</a> %e A214591 Some solutions for n=4 %e A214591 .....1........1........2........2........2........2........2........2 %e A214591 ....2.0......2.0......3.1......4.0......2.2......0.4......4.0......2.2 %e A214591 ...2.0.1....0.1.2....2.4.0....2.2.2....4.1.1....1.3.2....1.2.3....0.3.3 %e A214591 ..0.1.1.2..2.0.0.2..1.4.2.1..4.1.2.1..2.3.3.0..2.0.3.3..2.3.1.2..4.1.3.0 %Y A214591 Column 4 of A214595. %K A214591 nonn,changed %O A214591 1,1 %A A214591 _R. H. Hardin_, Jul 22 2012