A297763 Number of 2Xn 0..1 arrays with every 1 horizontally, diagonally or antidiagonally adjacent to 2, 3 or 4 neighboring 1s.

1, 2, 12, 31, 78, 225, 733, 2305, 7156, 22388, 70737, 223576, 705927, 2229237, 7044181, 22263130, 70360408, 222365159, 702781362, 2221173901, 7020142785, 22187534409, 70124998492, 221634512416, 700490315089, 2213945357924

Offset: 1

Author

R. H. Hardin, Jan 05 2018

Keywords

• nonn

Comments

Row 2 of A297762.

Examples

			Some solutions for n=7
..0..0..1..1..0..1..1. .0..1..1..1..1..1..0. .0..0..1..1..1..1..1
..0..1..1..0..0..1..1. .0..1..1..0..1..1..1. .0..0..0..1..0..1..1
		

Links

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

Crossrefs

Cf. A297762.

Formula

Empirical: a(n) = 4*a(n-1) -3*a(n-2) +a(n-3) +6*a(n-4) -18*a(n-5)