A278183 Number of n X 2 0..3 arrays with every element plus 1 mod 4 equal to some element at offset (-1,-1) (-1,0) (-1,1) (0,-1) (0,1) or (1,0), with upper left element zero.

0, 3, 28, 200, 1532, 11794, 90538, 695252, 5339294, 41003018, 314882364, 2418138526, 18570087298, 142608927356, 1095164819630, 8410314860218, 64586987065356, 495995568270926, 3808996439085090, 29251176423848812

Offset: 1

Author

R. H. Hardin, Nov 14 2016

Keywords

• nonn

Examples

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

Links

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

Crossrefs

Column 2 of A278188.

Formula

Empirical: a(n) = 8*a(n-1) - 4*a(n-2) + 15*a(n-3) - 26*a(n-4) + 14*a(n-5) - 16*a(n-6).

Empirical g.f.: x^2*(3 + 4*x - 12*x^2 - x^3 - 4*x^4) / (1 - 8*x + 4*x^2 - 15*x^3 + 26*x^4 - 14*x^5 + 16*x^6). - Colin Barker, Feb 08 2019