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A217949 Number of n-element 0..3 arrays with each element the minimum of 3 adjacent elements of a random 0..3 array of n+2 elements.

%I A217949 #11 May 17 2014 12:42:20
%S A217949 4,16,50,130,310,736,1821,4673,12107,31103,79039,199819,505477,
%T A217949 1282309,3259549,8288613,21064316,53497376,135833020,344914900,
%U A217949 875983319,2224986219,5651490601,14354263713,36457137516,92593166734,235168023403
%N A217949 Number of n-element 0..3 arrays with each element the minimum of 3 adjacent elements of a random 0..3 array of n+2 elements.
%C A217949 See A217954 and A228461 for more information. - _N. J. A. Sloane_, Sep 02 2013
%H A217949 R. H. Hardin, <a href="/A217949/b217949.txt">Table of n, a(n) for n = 1..210</a>
%F A217949 Empirical: a(n) = 4*a(n-1) -6*a(n-2) +4*a(n-3) +5*a(n-4) -4*a(n-5) +6*a(n-6) +4*a(n-7) +2*a(n-9) +a(n-10).
%F A217949 Empirical: G.f.: -x*(x^3+x^2+2) *(x^6+2*x^5+x^4+4*x^3+4*x^2+2) / ( (x^5+3*x^2-2*x+1) *(x^5+2*x^4+x^2+2*x-1) ). - _R. J. Mathar_, May 17 2014
%e A217949 Some solutions for n=4
%e A217949 ..2....0....1....0....1....0....0....0....0....2....2....3....1....2....1....1
%e A217949 ..0....3....2....0....1....2....0....2....2....3....2....3....2....2....3....1
%e A217949 ..0....0....1....2....1....3....2....2....2....2....2....2....2....3....1....1
%e A217949 ..0....0....0....3....0....0....2....1....0....1....0....1....2....2....0....3
%Y A217949 Column 3 of A217954. Cf. A217883, A217954.
%K A217949 nonn
%O A217949 1,1
%A A217949 _R. H. Hardin_, Oct 15 2012