|
A223426
|
|
5X5X5 triangular graph without horizontal edges coloring a rectangular array: number of nX2 0..14 arrays where 0..14 label nodes of a graph with edges 0,1 0,2 1,3 1,4 2,4 2,5 3,6 3,7 4,7 4,8 5,8 5,9 6,10 6,11 7,11 7,12 8,12 8,13 9,13 9,14 and every array movement to a horizontal or vertical neighbor moves along an edge of this graph
|
|
1
|
|
|
%I
%S 40,248,1648,11168,76384,524736,3613024,24906592,171802144,1185459328,
%T 8181293568,56467581344,389761873696,2690371352800,18570868118560,
%U 128190601161344,884876042394432,6108154188923040,42163659349783904
%N 5X5X5 triangular graph without horizontal edges coloring a rectangular array: number of nX2 0..14 arrays where 0..14 label nodes of a graph with edges 0,1 0,2 1,3 1,4 2,4 2,5 3,6 3,7 4,7 4,8 5,8 5,9 6,10 6,11 7,11 7,12 8,12 8,13 9,13 9,14 and every array movement to a horizontal or vertical neighbor moves along an edge of this graph
%C Column 2 of A223432
%H R. H. Hardin, <a href="/A223426/b223426.txt">Table of n, a(n) for n = 1..210</a>
%F Empirical: a(n) = 14*a(n-1) -57*a(n-2) +28*a(n-3) +225*a(n-4) -230*a(n-5) -192*a(n-6) +232*a(n-7) +28*a(n-8) -48*a(n-9)
%e Some solutions for n=3
%e ..4..2....2..5....7..3....9..5....7.11....8.12....4..2....4..2....3..1....8..4
%e ..2..0....5..2....3..6...14..9....4..7....5..8....2..5....7..4....1..0....5..8
%e ..4..2....9..5....7.11....9..5....8.12....8.13....0..2....3..7....4..1....8..4
%K nonn
%O 1,1
%A _R. H. Hardin_ Mar 20 2013
|
