A283036 Number of n X 2 0..1 arrays with no 1 equal to more than one of its horizontal and vertical neighbors, with the exception of exactly one element.

0, 4, 16, 68, 256, 924, 3232, 11044, 37104, 122984, 403280, 1310760, 4228960, 13558932, 43239776, 137251068, 433883696, 1366668772, 4290998336, 13433966724, 41949331616, 130685405648, 406258440928, 1260465716560, 3903760205760

Offset

1,2

Comments

Column 2 of A283042.

Links

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

Formula

Empirical: a(n) = 4*a(n-1) +2*a(n-2) -12*a(n-3) -11*a(n-4) +4*a(n-5) +6*a(n-6) -a(n-8).

Empirical: G.f.: -4*x^2*(x-1)*(1+x)/(x^4-3*x^2-2*x+1)^2. - R. J. Mathar, Mar 02 2017

Example

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

Crossrefs

Cf. A283042.

Sequence in context: A292759 A351049 A259815 * A307051 A158761 A179611

Adjacent sequences: A283033 A283034 A283035 * A283037 A283038 A283039

Keyword

nonn

Author

R. H. Hardin, Feb 27 2017

Status

approved