A297722 Number of 3Xn 0..1 arrays with every 1 horizontally, diagonally or antidiagonally adjacent to 1, 2 or 4 neighboring 1s.

1, 29, 145, 523, 2717, 14462, 68919, 332306, 1652441, 8140067, 39816114, 195543171, 961617387, 4722204339, 23186542778, 113898106759, 559470061363, 2747805117373, 13496167444555, 66289849507630, 325594360281088

Offset: 1

Author

R. H. Hardin, Jan 04 2018

Keywords

• nonn

Comments

Row 3 of A297720.

Examples

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

Links

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

Crossrefs

Cf. A297720.

Formula

Empirical: a(n) = 6*a(n-1) -5*a(n-2) +6*a(n-3) -17*a(n-4) -168*a(n-5) +284*a(n-6) +316*a(n-7) -636*a(n-8) +40*a(n-9) +732*a(n-10) -863*a(n-11) -414*a(n-12) +846*a(n-13) +17*a(n-14) -297*a(n-15) +188*a(n-16) +50*a(n-17) -52*a(n-18)