A219129 - OEIS

%I #10 Jul 25 2018 05:35:44

%S 9,15,87,205,899,2521,9709,29747,107261,344055,1199763,3940341,

%T 13507819,44905025,152598957,510467683,1726955485,5795447559,

%U 19561570195,65753998917,221680877531,745782497713,2512791313869,8457223721011

%N Number of 2 X n arrays of the minimum value of corresponding elements and their horizontal, diagonal or antidiagonal neighbors in a random 0..2 2 X n array.

%C Row 2 of A219128.

%H R. H. Hardin, <a href="/A219129/b219129.txt">Table of n, a(n) for n = 1..210</a>

%F Empirical: a(n) = 2*a(n-1) + 6*a(n-2) - 6*a(n-3) + 7*a(n-4) - 10*a(n-5) + 6*a(n-6) - 6*a(n-7) - 4*a(n-8).

%F Empirical g.f.: x*(9 - 3*x + 3*x^2 - 5*x^3 - 6*x^4 - 10*x^6 - 4*x^7) / (1 - 2*x - 6*x^2 + 6*x^3 - 7*x^4 + 10*x^5 - 6*x^6 + 6*x^7 + 4*x^8). - _Colin Barker_, Jul 25 2018

%e Some solutions for n=3:

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

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

%Y Cf. A219128.

%K nonn

%O 1,1

%A _R. H. Hardin_, Nov 12 2012