A283573 Number of 2Xn 0..1 arrays with no 1 equal to more than one of its horizontal, diagonal and antidiagonal neighbors, with the exception of exactly one element.

0, 4, 26, 72, 282, 908, 2832, 8856, 26750, 80088, 237190, 695272, 2024064, 5853676, 16835874, 48194664, 137385394, 390201476, 1104636144, 3118021376, 8778028806, 24653647608, 69091665822, 193246772832, 539525988960, 1503796131028

Offset

1,2

Comments

Row 2 of A283572.

Links

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

Formula

Empirical: a(n) = 2*a(n-1) +5*a(n-2) +2*a(n-3) -17*a(n-4) -24*a(n-5) -16*a(n-6).

Empirical: G.f.: 2*x^2*(2+9*x)/(-1+x+3*x^2+4*x^3)^2 . - R. J. Mathar, Mar 11 2017

Example

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

Crossrefs

Cf. A283572.

Sequence in context: A273981 A099442 A014450 * A200058 A142962 A247194

Adjacent sequences: A283570 A283571 A283572 * A283574 A283575 A283576

Keyword

nonn

Author

R. H. Hardin, Mar 11 2017

Status

approved