A280855 Number of nX4 0..2 arrays with no element equal to more than one of its king-move neighbors and with new values introduced in order 0 sequentially upwards.

11, 110, 96, 124, 216, 462, 1005, 2010, 3907, 7756, 15749, 31804, 63463, 126758, 254453, 511180, 1024877, 2052836, 4115191, 8254198, 16552251, 33182160, 66522097, 133381078, 267442273, 536212952, 1075064777, 2155474072, 4321733703

Offset: 1

Author

R. H. Hardin, Jan 09 2017

Keywords

• nonn

Comments

Column 4 of A280859.

Examples

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

Links

• R. H. Hardin, Table of n, a(n) for n = 1..210

Crossrefs

Cf. A280859.

Formula

Empirical: a(n) = a(n-1) +a(n-2) +a(n-3) +2*a(n-4) +3*a(n-5) -4*a(n-6) -3*a(n-7) -4*a(n-10) +2*a(n-12) for n>16