A205356 Number of (n+1) X 4 0..2 arrays with every 2 X 2 subblock having the same number of equal diagonal or antidiagonal elements, and new values 0..2 introduced in row major order.

194, 1562, 12866, 107330, 904514, 7690946, 65916482, 568956866, 4941735746, 43157726402, 378706958402, 3336772020674, 29503215149378, 261638552102594, 2326066810503746, 20723166492924866, 184949755175942978

Offset

1,1

Comments

Column 3 of A205361.

Links

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

Formula

Empirical: a(n) = 23*a(n-1) - 187*a(n-2) + 645*a(n-3) - 912*a(n-4) + 432*a(n-5).

Empirical g.f.: 2*x*(97 - 1450*x + 6609*x^2 - 10812*x^3 + 5652*x^4) / ((1 - x)*(1 - 4*x)*(1 - 9*x)*(1 - 9*x + 12*x^2)). - Colin Barker, Jun 11 2018

Example

Some solutions for n=4:
..0..1..1..2....0..0..0..0....0..0..0..0....0..1..0..2....0..0..1..0
..0..2..0..2....0..0..0..0....0..1..0..1....1..2..1..0....0..2..0..2
..1..1..1..1....0..0..0..0....1..2..1..2....1..1..1..1....2..1..2..1
..2..2..0..0....0..0..0..0....1..1..0..1....0..1..2..1....2..2..2..2
..0..1..1..1....0..0..0..0....1..2..1..1....0..0..1..0....2..1..2..0

Crossrefs

Cf. A205361.

Sequence in context: A278123 A158224 A205621 * A281807 A220160 A333875

Adjacent sequences: A205353 A205354 A205355 * A205357 A205358 A205359

Keyword

nonn

Author

R. H. Hardin, Jan 26 2012

Status

approved