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 A223210 #7 Jul 23 2025 03:52:01 %S A223210 6,126,15498,9640008,32213930742,568826898735456,53598993642186546600, %T A223210 26904643609262481062550540,72104047201942444207678110553554, %U A223210 1031832360324996701256333234422715357000 %N A223210 3X3X3 triangular graph coloring a rectangular array: number of n X n 0..5 arrays where 0..5 label nodes of a graph with edges 0,1 0,2 1,2 1,3 1,4 2,4 3,4 2,5 4,5 and every array movement to a horizontal or vertical neighbor moves along an edge of this graph. %C A223210 Diagonal of A223218 %e A223210 Some solutions for n=3 %e A223210 ..3..4..3....2..4..2....2..4..2....2..0..1....1..4..3....0..2..0....4..3..4 %e A223210 ..4..1..4....4..2..1....4..3..4....4..2..4....0..1..4....2..4..1....2..4..2 %e A223210 ..1..2..1....3..1..3....5..4..3....2..4..1....2..4..1....4..1..2....4..3..4 %K A223210 nonn %O A223210 1,1 %A A223210 _R. H. Hardin_ Mar 18 2013