A228478 Number of n X 4 binary arrays with top left value 1 and no two ones adjacent horizontally, vertically or antidiagonally.

3, 9, 41, 172, 728, 3084, 13050, 55252, 233875, 990055, 4191028, 17741339, 75101906, 317918500, 1345800258, 5696989354, 24116274286, 102088075950, 432155280235, 1829382955772, 7744072911728, 32781908823977, 138771103836595

Offset: 1

Author

R. H. Hardin, Aug 22 2013

Keywords

• nonn

Comments

Same recurrences as A228285 except in addition a smaller one for column 5.

Examples

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

Links

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

Crossrefs

Column 4 of A228482.

Formula

a(n) = a(n-1) + 10*a(n-2) + 15*a(n-3) + 4*a(n-4) - 6*a(n-5) - a(n-6) + 3*a(n-7) - a(n-8).

Empirical g.f.: x*(3 + 6*x + 2*x^2 - 4*x^3 - x^4 + 3*x^5 - x^6) / (1 - x - 10*x^2 - 15*x^3 - 4*x^4 + 6*x^5 + x^6 - 3*x^7 + x^8). - Colin Barker, Sep 11 2018