A240889 Number of nX4 0..2 arrays with no element equal to a different number of vertical neighbors than horizontal neighbors, with new values 0..2 introduced in row major order.

4, 36, 289, 2362, 19065, 154858, 1255585, 10186158, 82615013, 670126562, 5435464261, 44088312610, 357608156789, 2900631278142, 23527575671521, 190836751334954, 1547913820098569, 12555429390762018, 101839521640750945

Offset: 1

Author

R. H. Hardin, Apr 14 2014

Keywords

• nonn

Comments

Column 4 of A240893

Examples

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

Links

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

Formula

Empirical: a(n) = 8*a(n-1) +9*a(n-2) -63*a(n-3) +36*a(n-4) -405*a(n-5) -608*a(n-6) +600*a(n-7) +424*a(n-8) +4600*a(n-9) +10176*a(n-10) +9216*a(n-11) -2560*a(n-12) -29312*a(n-13) -40448*a(n-14) -30720*a(n-15) -16384*a(n-16)