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 A214902 #6 Jul 22 2025 23:19:29 %S A214902 5,9,29,182,1802,29162,657722,21063242,892354322,48771558002, %T A214902 3355941877202,288300261981602,29970020819138402,3775596638574103202, %U A214902 566303743347081854402,100233490058027413401602 %N A214902 Number of nXnXn triangular 0..4 arrays with every horizontal row nondecreasing and having the same average value. %C A214902 Column 4 of A214906 %H A214902 R. H. Hardin, <a href="/A214902/b214902.txt">Table of n, a(n) for n = 1..120</a> %e A214902 Some solutions for n=4 %e A214902 .....1........2........3........2........1........3........2........2 %e A214902 ....1.1......0.4......2.4......2.2......0.2......3.3......1.3......0.4 %e A214902 ...0.1.2....0.2.4....3.3.3....1.1.4....0.0.3....2.3.4....1.1.4....0.2.4 %e A214902 ..0.0.0.4..0.2.3.3..0.4.4.4..1.1.2.4..1.1.1.1..1.3.4.4..0.1.3.4..1.2.2.3 %K A214902 nonn %O A214902 1,1 %A A214902 _R. H. Hardin_ Jul 29 2012