A223605 - OEIS

A223605

Petersen graph (8,2) coloring a rectangular array: number of 7 X n 0..15 arrays where 0..15 label nodes of a graph with edges 0,1 0,8 8,14 8,10 1,2 1,9 9,15 9,11 2,3 2,10 10,12 3,4 3,11 11,13 4,5 4,12 12,14 5,6 5,13 13,15 6,7 6,14 7,0 7,15 and every array movement to a horizontal, diagonal or antidiagonal neighbor moves along an edge of this graph.

%I #6 Mar 02 2023 12:27:47

%S 268435456,1180256,236213312,20631729648,3355919411936,

%T 488183756623568,78546923445668960,12456911118159504464,

%U 2003721183655242155360,321631735635728311838256,51731199109756440589448464

%N Petersen graph (8,2) coloring a rectangular array: number of 7 X n 0..15 arrays where 0..15 label nodes of a graph with edges 0,1 0,8 8,14 8,10 1,2 1,9 9,15 9,11 2,3 2,10 10,12 3,4 3,11 11,13 4,5 4,12 12,14 5,6 5,13 13,15 6,7 6,14 7,0 7,15 and every array movement to a horizontal, diagonal or antidiagonal neighbor moves along an edge of this graph.

%C Row 7 of A223599.

%H R. H. Hardin, <a href="/A223605/b223605.txt">Table of n, a(n) for n = 1..28</a>

%e Some solutions for n=3

%e ..0..8..0....0..8..0....0..8..0....0..8..0....0..8..0....0..8..0....0..8..0

%e ..0..8..0...10..8.10....0..8..0...10..8.10....0..8..0...10..8.10...14..8..0

%e ..0..8..0...14.12.10....0..7..0....0..8.10....0..1..0...10..2.10...14..8.10

%e ..0..1..0...10.12.14...15..7.15...14..8.10....2..1..2...10..2..1...10.12.10

%e ..0..7..0...10.12.10....6..7.15...14..8.10....9..1..0...10..2..3....4.12.14

%e ..0..7.15....4.12.10....6..7.15....0..8.14....0..1..2...10..2.10...14.12.10

%Y Cf. A223599.

%K nonn

%O 1,1

%A _R. H. Hardin_, Mar 23 2013