cp's OEIS Frontend

A223595 Petersen graph (8,2) coloring a rectangular array: number of nX4 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 A223595 #6 Jul 23 2025 04:16:37
%S A223595 432,6736,122608,2372080,47659632,982848688,20631729648,438231627440,
%T A223595 9379905920496,201754894742320,4353130535839216,94109174401819824,
%U A223595 2037032269494019568,44126508340010479152,956337724569802746864
%N A223595 Petersen graph (8,2) coloring a rectangular array: number of nX4 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 A223595 Column 4 of A223599
%H A223595 R. H. Hardin, <a href="/A223595/b223595.txt">Table of n, a(n) for n = 1..210</a>
%F A223595 Empirical: a(n) = 45*a(n-1) -639*a(n-2) +2781*a(n-3) +4328*a(n-4) -42674*a(n-5) +32672*a(n-6) +131496*a(n-7) -190080*a(n-8) +31104*a(n-9)
%e A223595 Some solutions for n=3
%e A223595 .10.12.10.12...13.15.13..5...10..8.14.12....2..3..2.10...13.15..9.15
%e A223595 .10..8.14..8....9.11.13..5...10..8.14.12...11..3..2..3....9.11..9..1
%e A223595 .10..8.10.12....9.11.13.15....0..8.14..6....2..3..2.10...13.15..9..1
%K A223595 nonn
%O A223595 1,1
%A A223595 _R. H. Hardin_ Mar 23 2013