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 A214904 #6 Jul 22 2025 23:19:44 %S A214904 7,16,88,1184,31412,1563440,130431428,17983769774,3834925737542, %T A214904 1241935634661854,580437179573006186,386026538656132081970, %U A214904 351778685344619628965378,434522760040678152959511554 %N A214904 Number of nXnXn triangular 0..6 arrays with every horizontal row nondecreasing and having the same average value. %C A214904 Column 6 of A214906 %H A214904 R. H. Hardin, <a href="/A214904/b214904.txt">Table of n, a(n) for n = 1..90</a> %e A214904 Some solutions for n=4 %e A214904 .....5........4........2........3........2........4........3........4 %e A214904 ....4.6......3.5......2.2......0.6......0.4......3.5......2.4......4.4 %e A214904 ...5.5.5....0.6.6....0.2.4....0.4.5....2.2.2....3.3.6....2.3.4....3.4.5 %e A214904 ..4.5.5.6..2.4.5.5..1.1.3.3..0.3.4.5..1.1.2.4..0.4.6.6..1.1.5.5..2.4.4.6 %K A214904 nonn %O A214904 1,1 %A A214904 _R. H. Hardin_ Jul 29 2012