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%I A196537 #7 Jul 25 2012 04:55:59
%S A196537 1,3,2,7,19,35,77,176,377,819,1801,3927,8562,18711,40855,89179,194729,
%T A196537 425184,928305,2026855,4425441,9662395,21096706,46062279,100571611,
%U A196537 219586403,479441557,1046805072,2285577449,4990293595,10895727817
%N A196537 Number of nX1 0..4 arrays with each element equal to the number its horizontal and vertical neighbors less than or equal to itself
%C A196537 Column 1 of A196544
%H A196537 R. H. Hardin, <a href="/A196537/b196537.txt">Table of n, a(n) for n = 1..200</a>
%F A196537 Empirical: a(n) = a(n-1) +a(n-2) +3*a(n-3) +a(n-4).
%F A196537 Empirical: G.f. x*(x-1)*(x^2+3*x+1) / ( -1+x+x^2+3*x^3+x^4 ). - _R. J. Mathar_, Jul 25 2012
%e A196537 All solutions for n=4
%e A196537 ..0....0....1....0....0....1....0
%e A196537 ..2....1....0....2....2....1....2
%e A196537 ..2....2....2....1....1....2....0
%e A196537 ..0....0....0....1....0....0....1
%K A196537 nonn
%O A196537 1,2
%A A196537 _R. H. Hardin_ Oct 03 2011

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