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A202797 Number of n X 3 binary arrays with every one adjacent to another one horizontally or vertically.

%I A202797 #8 Jun 01 2018 14:18:24
%S A202797 4,36,250,1718,11988,83518,581518,4049700,28202318,196400270,
%T A202797 1367728548,9524845126,66330898142,461927514284,3216857242006,
%U A202797 22402152254494,156008298702684,1086439775514766,7565952552767646,52689195775528564
%N A202797 Number of n X 3 binary arrays with every one adjacent to another one horizontally or vertically.
%C A202797 Column 3 of A202802.
%H A202797 R. H. Hardin, <a href="/A202797/b202797.txt">Table of n, a(n) for n = 1..210</a>
%F A202797 Empirical: a(n) = 7*a(n-1) -3*a(n-2) +19*a(n-3) -3*a(n-4) +25*a(n-5) +24*a(n-6) -22*a(n-7) -16*a(n-8).
%F A202797 Empirical g.f.: 2*x*(2 + 4*x + 5*x^2 + 20*x^4 + 7*x^5 - 16*x^6 - 8*x^7) / (1 - 7*x + 3*x^2 - 19*x^3 + 3*x^4 - 25*x^5 - 24*x^6 + 22*x^7 + 16*x^8). - _Colin Barker_, Jun 01 2018
%e A202797 Some solutions for n=5:
%e A202797 ..0..0..0....0..1..0....0..0..1....0..1..1....0..1..1....0..0..1....0..0..0
%e A202797 ..1..0..0....1..1..1....0..0..1....0..1..0....0..0..1....0..0..1....1..0..0
%e A202797 ..1..0..0....0..0..1....1..0..1....1..0..0....1..1..0....0..1..0....1..1..1
%e A202797 ..0..1..1....0..1..0....1..1..1....1..1..1....0..0..0....0..1..1....1..1..1
%e A202797 ..0..1..0....0..1..1....0..1..0....0..0..1....0..1..1....0..0..1....0..1..0
%Y A202797 Cf. A202802.
%K A202797 nonn
%O A202797 1,1
%A A202797 _R. H. Hardin_, Dec 24 2011