A222836 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.

55, 1536, 1944, 4056, 9600, 24576, 55296, 124416, 279936, 645504, 1476096, 3393024, 7742976, 17750400, 40560000, 92952576, 212557824, 486864384, 1113680256, 2550116736, 5834651136, 13357979136, 30567200256, 69973632384, 160134620544

Offset: 1

Author

R. H. Hardin Mar 06 2013

Keywords

• nonn

Comments

Column 6 of A222838

Examples

			Some solutions for n=4
..0..1..2..2..3..0....0..1..1..2..0..3....0..1..2..2..1..3....0..1..2..0..3..1
..0..3..3..0..1..1....0..2..3..3..1..2....0..1..3..3..0..0....2..1..3..0..2..2
..2..2..1..0..2..3....1..2..0..0..1..2....3..2..0..1..2..2....2..0..3..1..1..3
..3..0..1..3..2..0....3..3..1..2..3..3....3..2..0..1..3..3....3..0..2..2..0..0
		

Links

• R. H. Hardin, Table of n, a(n) for n = 1..112

Formula

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