A297596 Number of 3 X n 0..1 arrays with every 1 horizontally, diagonally or antidiagonally adjacent to 1 or 5 neighboring 1s.

1, 9, 25, 49, 145, 443, 1141, 3009, 8455, 23151, 62211, 169651, 464469, 1262947, 3434407, 9364725, 25517397, 69467533, 189209921, 515479315, 1403998341, 3823905513, 10415880295, 28371283095, 77275911315, 210482481315

Offset: 1

Author

R. H. Hardin, Jan 01 2018

Keywords

• nonn

Examples

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

Links

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

Crossrefs

Row 3 of A297595.

Formula

Empirical: a(n) = a(n-1) + a(n-2) + 8*a(n-3) + 7*a(n-4) - 8*a(n-6) - 6*a(n-7).

Empirical g.f.: x*(1 + 8*x + 15*x^2 + 7*x^3 - 8*x^4 - 14*x^5 - 6*x^6) / (1 - x - x^2 - 8*x^3 - 7*x^4 + 8*x^6 + 6*x^7). - Colin Barker, Mar 01 2019