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A281696 Number of 4Xn 0..2 arrays with no element equal to more than one of its horizontal, diagonal or antidiagonal neighbors, with the exception of exactly two elements, and with new values introduced in order 0 sequentially upwards. 1

%I

%S 0,222,19326,402470,7497214,126719222,1847808312,25489973264,

%T 335106626139,4243531978116,52250869377772,628947105706014,

%U 7431279191300006,86458169278267534,992830171072101269

%N Number of 4Xn 0..2 arrays with no element equal to more than one of its horizontal, diagonal or antidiagonal neighbors, with the exception of exactly two elements, and with new values introduced in order 0 sequentially upwards.

%C Row 4 of A281693.

%H R. H. Hardin, <a href="/A281696/b281696.txt">Table of n, a(n) for n = 1..109</a>

%e Some solutions for n=3

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

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

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

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

%Y Cf. A281693.

%K nonn

%O 1,2

%A _R. H. Hardin_, Jan 27 2017

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Last modified August 7 06:02 EDT 2020. Contains 336274 sequences. (Running on oeis4.)