A295412 Number of nX4 0..1 arrays with each 1 horizontally or vertically adjacent to 1, 2 or 3 1s.

7, 126, 1534, 19026, 240439, 3019079, 37927609, 476686533, 5990217198, 75274793595, 945936754846, 11887043481205, 149377582878265, 1877141810399248, 23588956324272434, 296428780394920491

Offset: 1

Author

R. H. Hardin, Nov 22 2017

Keywords

• nonn

Comments

Column 4 of A295416.

Examples

			Some solutions for n=5
..0..1..1..1. .0..0..0..0. .0..0..1..1. .0..0..0..0. .0..0..0..0
..1..0..1..1. .0..1..1..1. .0..0..0..1. .0..1..1..0. .1..1..0..1
..1..0..1..1. .1..1..0..1. .0..0..0..1. .0..0..1..0. .1..0..0..1
..1..0..0..0. .0..1..0..1. .1..1..0..0. .0..0..1..1. .1..1..0..0
..1..0..0..0. .0..1..0..0. .0..0..1..1. .1..1..0..1. .1..1..1..1
		

Links

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

Crossrefs

Cf. A295416.

Formula

Empirical: a(n) = 9*a(n-1) +23*a(n-2) +218*a(n-3) +534*a(n-4) +1923*a(n-5) +3128*a(n-6) -1379*a(n-7) -8708*a(n-8) -5083*a(n-9) +7804*a(n-10) +9844*a(n-11) -968*a(n-12) -6624*a(n-13) -3072*a(n-14)