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A280674 Number of 2 X n 0..2 arrays with no element equal to more than one of its horizontal and antidiagonal neighbors and with new values introduced in order 0 sequentially upwards. 1

%I

%S 2,11,59,338,1917,10893,61880,351541,1997095,11345458,64453321,

%T 366158041,2080136592,11817214849,67133363931,381383313234,

%U 2166631062437,12308588230773,69924846394792,397241669934877,2256722073320511

%N Number of 2 X n 0..2 arrays with no element equal to more than one of its horizontal and antidiagonal neighbors and with new values introduced in order 0 sequentially upwards.

%H R. H. Hardin, <a href="/A280674/b280674.txt">Table of n, a(n) for n = 1..210</a>

%F Empirical: a(n) = 5*a(n-1) + 6*a(n-2) - 11*a(n-3) - 7*a(n-4) + 4*a(n-5) for n>6.

%F Empirical g.f.: x*(1 - x)*(2 + 3*x - x^2)*(1 - 2*x^2) / ((1 + x)*(1 - 6*x + 11*x^3 - 4*x^4)). - _Colin Barker_, Feb 14 2019

%e Some solutions for n=4:

%e ..0..0..1..0. .0..1..0..2. .0..1..1..2. .0..1..0..1. .0..0..1..2

%e ..2..0..2..1. .1..2..0..2. .0..2..0..2. .1..0..2..2. .1..0..0..1

%Y Row 2 of A280673.

%K nonn

%O 1,1

%A _R. H. Hardin_, Jan 07 2017

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Last modified October 17 04:49 EDT 2021. Contains 348048 sequences. (Running on oeis4.)