login

Reminder: The OEIS is hiring a new managing editor, and the application deadline is January 26.

Petersen graph (3,1) coloring a rectangular array: number of n X n 0..5 arrays where 0..5 label nodes of a graph with edges 0,1 0,3 3,5 3,4 1,2 1,4 4,5 2,0 2,5 and every array movement to a horizontal or antidiagonal neighbor moves along an edge of this graph, with the array starting at 0
1

%I #6 Dec 18 2015 18:18:31

%S 1,27,3249,1795473,4715559621,59043582882099,3541866135681593043,

%T 1020092567883788131348995,1412857454503152706541498629089,

%U 9420448274769727958157865214329990383

%N Petersen graph (3,1) coloring a rectangular array: number of n X n 0..5 arrays where 0..5 label nodes of a graph with edges 0,1 0,3 3,5 3,4 1,2 1,4 4,5 2,0 2,5 and every array movement to a horizontal or antidiagonal neighbor moves along an edge of this graph, with the array starting at 0

%C Diagonal of A223556

%H R. H. Hardin, <a href="/A223551/b223551.txt">Table of n, a(n) for n = 1..12</a>

%e Some solutions for n=3

%e ..0..1..4....0..3..4....0..3..4....0..3..0....0..3..4....0..2..0....0..3..4

%e ..0..3..0....5..3..4....5..3..0....5..3..4....5..3..4....0..2..1....4..5..4

%e ..0..2..1....4..5..2....4..3..4....4..3..0....0..3..0....5..4..1....4..1..2

%K nonn

%O 1,2

%A _R. H. Hardin_ Mar 22 2013