A222836 - OEIS

%I #4 Mar 06 2013 17:55:55

%S 55,1536,1944,4056,9600,24576,55296,124416,279936,645504,1476096,

%T 3393024,7742976,17750400,40560000,92952576,212557824,486864384,

%U 1113680256,2550116736,5834651136,13357979136,30567200256,69973632384,160134620544

%N Number of nX6 0..3 arrays with no element equal to another at a city block distance of exactly two, and new values 0..3 introduced in row major order

%C Column 6 of A222838

%H R. H. Hardin, <a href="/A222836/b222836.txt">Table of n, a(n) for n = 1..112</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 n=4

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

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

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

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

%K nonn

%O 1,1

%A _R. H. Hardin_ Mar 06 2013