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 A195226 Number of lower triangles of an n X n 0..2 array with each element differing from all of its diagonal, vertical, antidiagonal and horizontal neighbors by one or less 1

%I

%S 3,15,155,3151,127785,10322065,1663418313,535153390177,

%T 343932423395227,441776066934784687,1134608168927438377475,

%U 5828490619001307113164495,59904949456032239303490933489,1232191818850202836476827846621041

%N Number of lower triangles of an n X n 0..2 array with each element differing from all of its diagonal, vertical, antidiagonal and horizontal neighbors by one or less

%C Column 2 of A195232

%H R. H. Hardin, <a href="/A195226/b195226.txt">Table of n, a(n) for n = 1..20</a>

%e Some solutions for n=4

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

%e ..1.1......1.2......1.1......1.2......1.1......1.1......0.0......1.1

%e ..0.1.1....1.1.2....1.1.1....1.2.2....1.1.0....0.1.1....1.0.1....0.0.0

%e ..0.1.1.0..1.1.1.2..0.1.0.0..1.1.2.2..1.1.0.0..0.0.1.1..1.0.0.0..1.1.0.0

%K nonn

%O 1,1

%A _R. H. Hardin_ Sep 13 2011

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Last modified March 21 17:39 EDT 2023. Contains 361408 sequences. (Running on oeis4.)