A284159 Number of n X 2 0..1 arrays with the number of 1's horizontally or vertically adjacent to some 0 equal to the number of 0's adjacent to some 1, with top left element zero.

2, 4, 13, 42, 134, 467, 1689, 6210, 23178, 87336, 331172, 1262635, 4836199, 18592719, 71697865, 277195002, 1074041216, 4169581090, 16214541562, 63150645344, 246288102302, 961707595682, 3759467766802, 14711266580343, 57620439699189

Offset: 1

Author

R. H. Hardin, Mar 21 2017

Keywords

• nonn

Comments

Column 2 of A284165.

Examples

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

Links

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

Crossrefs

Cf. A284165.