A233199 - OEIS

A233199

Number of nX5 0..7 arrays with no element x(i,j) adjacent to itself or value 7-x(i,j) horizontally, antidiagonally or vertically, top left element zero, and 1 appearing before 2 3 4 5 and 6, 2 appearing before 3 4 and 5, and 3 appearing before 4 in row major order (unlabelled 8-colorings with no clashing color pairs)

%I #4 Dec 05 2013 17:52:13

%S 48,8256,2779136,981532672,352524959744,127365174788096,

%T 46111939268444160,16706602064729341952,6054323596680792899584,

%U 2194196637563524913037312,795235812066308877870694400

%N Number of nX5 0..7 arrays with no element x(i,j) adjacent to itself or value 7-x(i,j) horizontally, antidiagonally or vertically, top left element zero, and 1 appearing before 2 3 4 5 and 6, 2 appearing before 3 4 and 5, and 3 appearing before 4 in row major order (unlabelled 8-colorings with no clashing color pairs)

%C Column 5 of A233202

%H R. H. Hardin, <a href="/A233199/b233199.txt">Table of n, a(n) for n = 1..210</a>

%F Empirical: a(n) = 736*a(n-1) -203776*a(n-2) +33062912*a(n-3) -3665821696*a(n-4) +270851375104*a(n-5) -10685878632448*a(n-6) -116548232544256*a(n-7) +35184372088832000*a(n-8) -1423137482249076736*a(n-9) +18446744073709551616*a(n-10) for n>11

%e Some solutions for n=2

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

%e ..5..3..0..5..4....4..0..3..0..1....3..7..1..0..1....4..0..3..6..2

%K nonn

%O 1,1

%A _R. H. Hardin_, Dec 05 2013