A259421 Number of (n+1) X (2+1) 0..1 arrays with each 2 X 2 subblock having clockwise pattern 0000 0001 0011 or 0111.

43, 243, 1366, 7695, 43347, 244228, 1376077, 7753553, 43687910, 246163281, 1387029593, 7815349472, 44036333771, 248126951851, 1398095180302, 7877701886559, 44387669863035, 250106600625676, 1409249728938893

Offset: 1

Author

R. H. Hardin, Jun 26 2015

Keywords

• nonn

Examples

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

Links

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

Crossrefs

Column 2 of A259427.

Formula

Empirical: a(n) = 6*a(n-1) + 2*a(n-2) - 22*a(n-3) - 6*a(n-4) + 6*a(n-5) + a(n-6).

Empirical g.f.: x*(43 - 15*x - 178*x^2 - 41*x^3 + 49*x^4 + 8*x^5) / (1 - 6*x - 2*x^2 + 22*x^3 + 6*x^4 - 6*x^5 - x^6). - Colin Barker, Dec 25 2018