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%I #8 Feb 14 2019 12:42:42
%S 0,10,646,22632,610448,14262832,304584096,6117000704,117496694272,
%T 2181977379072,39462274293248,698659360847872,12154771113160704,
%U 208386384523096064,3528538532937736192,59112926060691652608
%N Number of n X 3 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="/A280897/b280897.txt">Table of n, a(n) for n = 1..210</a>
%F Empirical: a(n) = 42*a(n-1) - 564*a(n-2) + 2072*a(n-3) + 4512*a(n-4) + 2688*a(n-5) + 512*a(n-6) for n>8.
%F Empirical g.f.: 2*x^2*(5 + 113*x + 570*x^2 + 1764*x^3 + 2416*x^4 + 1344*x^5 + 256*x^6) / (1 - 14*x - 8*x^2)^3. - _Colin Barker_, Feb 14 2019
%e Some solutions for n=4:
%e ..0..0..0. .0..1..1. .0..1..2. .0..1..0. .0..1..2. .0..0..0. .0..1..2
%e ..1..0..1. .1..2..0. .2..2..1. .0..1..0. .0..1..2. .1..2..1. .1..1..2
%e ..2..2..1. .0..0..2. .2..1..1. .2..2..2. .1..1..1. .1..1..2. .0..0..2
%e ..0..2..0. .0..1..2. .0..0..1. .1..2..0. .0..2..2. .2..0..1. .2..2..0
%Y Column 3 of A280902.
%K nonn
%O 1,2
%A _R. H. Hardin_, Jan 10 2017
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