A183358 - OEIS

%I #5 Mar 31 2012 12:35:50

%S 324,9216,11664,24336,57600,147456,331776,746496,1679616,3873024,

%T 8856576,20358144,46457856,106502400,243360000,557715456,1275346944,

%U 2921186304,6682081536,15300700416,35007906816,80147874816,183403201536

%N One quarter the number of nX6 1..4 arrays with no two neighbors of any element equal to each other

%C Column 6 of A183362

%H R. H. Hardin, <a href="/A183358/b183358.txt">Table of n, a(n) for n = 1..106</a>

%F Empirical: a(n)=2*a(n-1)+2*a(n-2)-4*a(n-3)+4*a(n-4)-4*a(n-5)+2*a(n-6)-6*a(n-7)+a(n-10) for n>14

%e Some solutions for 5X6 with a(1,1)=1

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

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

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

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

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

%K nonn

%O 1,1

%A _R. H. Hardin_ Jan 04 2011