A233250 - OEIS

A233250

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

%I #6 Dec 18 2015 18:18:48

%S 1,10,4672,23896064,1159192379392,525597937107992576,

%T 2242238966451009797226496,90075874398562137894702244954112,

%U 34144912055691090021767126315871433129984

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

%C Diagonal of A233256

%H R. H. Hardin, <a href="/A233250/b233250.txt">Table of n, a(n) for n = 1..15</a>

%e Some solutions for n=3

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

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

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

%K nonn

%O 1,2

%A _R. H. Hardin_, Dec 06 2013