A283197 - OEIS

%I #8 Mar 22 2018 09:47:24

%S 0,0,6,36,176,824,3668,15808,66640,276184,1129482,4570084,18329920,

%T 72981648,288779688,1136580576,4452663936,17372989712,67541322638,

%U 261743811012,1011439313456,3898369209992,14990343112316,57519762677984

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

%C Column 2 of A283203.

%H R. H. Hardin, <a href="/A283197/b283197.txt">Table of n, a(n) for n = 1..210</a>

%F Empirical: a(n) = 6*a(n-1) - 5*a(n-2) - 8*a(n-3) - 18*a(n-4) - 4*a(n-5) + 6*a(n-6) + 8*a(n-7) + 3*a(n-8) - 2*a(n-9) - a(n-10).

%F Empirical g.f.: 2*x^3*(1 + x)*(3 - 3*x - 2*x^2) / (1 - 3*x - 2*x^2 - 2*x^3 + x^4 + x^5)^2. - _Colin Barker_, Mar 22 2018

%e Some solutions for n=4:

%e ..1..0. .1..1. .0..0. .0..1. .1..0. .0..1. .0..1. .0..0. .0..0. .1..1

%e ..0..1. .1..0. .0..1. .1..1. .1..1. .1..1. .1..0. .1..1. .1..1. .1..1

%e ..1..1. .1..1. .1..1. .0..1. .1..0. .0..1. .1..1. .1..1. .1..1. .1..0

%e ..0..1. .1..0. .1..1. .1..1. .1..1. .0..0. .1..0. .1..0. .0..1. .0..0

%Y Cf. A283203.

%K nonn

%O 1,3

%A _R. H. Hardin_, Mar 02 2017