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A218051 Number of n X 1 arrays of the minimum value of corresponding elements and their horizontal, vertical, diagonal or antidiagonal neighbors in a random 0..3 n X 1 array.

%I A218051 #8 Feb 19 2018 09:11:29
%S A218051 4,4,16,36,94,236,602,1528,3882,9858,25038,63592,161514,410218,
%T A218051 1041884,2646208,6720920,17069998,43354902,110114102,279671154,
%U A218051 710317326,1804085608,4582071648,11637685314,29557748082,75071670020,190669317026
%N A218051 Number of n X 1 arrays of the minimum value of corresponding elements and their horizontal, vertical, diagonal or antidiagonal neighbors in a random 0..3 n X 1 array.
%C A218051 Column 1 of A218056.
%H A218051 R. H. Hardin, <a href="/A218051/b218051.txt">Table of n, a(n) for n = 1..210</a>
%F A218051 Empirical: a(n) = 2*a(n-1) + a(n-2) + 2*a(n-4) + a(n-5).
%F A218051 Empirical g.f.: 2*x*(2 - 2*x + 2*x^2 - x^4) / (1 - 2*x - x^2 - 2*x^4 - x^5). - _Colin Barker_, Feb 19 2018
%e A218051 All solutions for n=3:
%e A218051 ..2....0....3....2....3....2....3....2....0....1....1....1....1....3....0....0
%e A218051 ..1....0....3....2....2....2....1....0....0....1....1....1....0....0....0....0
%e A218051 ..1....0....3....3....2....2....1....0....2....2....3....1....0....0....1....3
%K A218051 nonn
%O A218051 1,1
%A A218051 _R. H. Hardin_, Oct 19 2012