Year-end appeal: Please make a donation to the OEIS Foundation to support ongoing development and maintenance of the OEIS. We are now in our 61st year, we have over 378,000 sequences, and we’ve reached 11,000 citations (which often say “discovered thanks to the OEIS”).
%I #8 Nov 16 2021 21:42:13
%S 0,4,16,68,256,924,3232,11044,37104,122984,403280,1310760,4228960,
%T 13558932,43239776,137251068,433883696,1366668772,4290998336,
%U 13433966724,41949331616,130685405648,406258440928,1260465716560,3903760205760
%N 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.
%C Column 2 of A283042.
%H R. H. Hardin, <a href="/A283036/b283036.txt">Table of n, a(n) for n = 1..210</a>
%F 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).
%F 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
%e Some solutions for n=4
%e ..1..0. .1..1. .1..1. .1..0. .1..1. .1..1. .0..1. .0..0. .1..1. .1..1
%e ..0..0. .0..1. .1..0. .1..1. .0..0. .0..1. .0..1. .0..1. .1..0. .0..0
%e ..1..1. .0..0. .0..1. .1..0. .0..1. .0..0. .0..1. .1..0. .0..0. .1..0
%e ..0..1. .1..0. .0..1. .0..1. .1..1. .0..1. .1..0. .1..1. .1..0. .1..1
%Y Cf. A283042.
%K nonn
%O 1,2
%A _R. H. Hardin_, Feb 27 2017