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%I #9 Feb 14 2019 11:11:27
%S 0,1,9,124,1464,15768,159920,1554304,14632704,134378112,1209699584,
%T 10713166848,93585811456,808068888576,6907767091200,58538748477440,
%U 492296387559424,4112143740076032,34141836642680832,281936660687224832
%N Number of n X 2 0..2 arrays with no element equal to more than one of its horizontal and antidiagonal neighbors, with the exception of exactly two elements, and with new values introduced in order 0 sequentially upwards.
%H R. H. Hardin, <a href="/A280896/b280896.txt">Table of n, a(n) for n = 1..210</a>
%F Empirical: a(n) = 24*a(n-1) - 204*a(n-2) + 704*a(n-3) - 816*a(n-4) + 384*a(n-5) - 64*a(n-6) for n>8.
%F Empirical g.f.: x^2*(1 - 15*x + 112*x^2 - 380*x^3 + 408*x^4 - 192*x^5 + 32*x^6) / (1 - 8*x + 4*x^2)^3. - _Colin Barker_, Feb 14 2019
%e Some solutions for n=4:
%e ..0..0. .0..1. .0..0. .0..1. .0..1. .0..0. .0..1. .0..1. .0..0. .0..0
%e ..1..2. .2..2. .1..0. .1..1. .1..2. .1..0. .0..2. .1..1. .0..1. .1..1
%e ..0..0. .0..0. .0..0. .2..1. .0..0. .1..1. .2..2. .1..2. .1..1. .1..0
%e ..0..0. .0..0. .0..2. .1..1. .0..0. .1..1. .2..1. .0..1. .0..0. .0..0
%Y Column 2 of A280902.
%K nonn
%O 1,3
%A _R. H. Hardin_, Jan 10 2017
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