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 A196423 Number of n X 1 0..4 arrays with each element equal to the number its horizontal and vertical neighbors less than itself. 5

%I

%S 1,3,5,11,26,55,119,263,573,1248,2729,5959,13005,28399,62010,135383,

%T 295595,645407,1409161,3076736,6717713,14667339,32024421,69921635,

%U 152665786,333328023,727783135,1589030151,3469463141,7575170720

%N Number of n X 1 0..4 arrays with each element equal to the number its horizontal and vertical neighbors less than itself.

%C Column 1 of A196430.

%H R. H. Hardin, <a href="/A196423/b196423.txt">Table of n, a(n) for n = 1..200</a>

%F Empirical: a(n) = a(n-1) +a(n-2) +3*a(n-3) +a(n-4).

%F Empirical: G.f. -x*(1+x)^2 / ( -1+x+x^2+3*x^3+x^4 ). - _R. J. Mathar_, Jul 25 2012

%e All solutions for n=3:

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

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

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

%Y Cf. A196430.

%K nonn

%O 1,2

%A _R. H. Hardin_, Oct 02 2011

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Last modified September 26 01:54 EDT 2021. Contains 347664 sequences. (Running on oeis4.)