|
%I #7 Sep 26 2018 06:20:33
%S 0,2,14,40,356,1840,10128,60808,337016,1932520,11047240,62712776,
%T 358084712,2039935624,11622103656,66251217992,377502949416,
%U 2151360049288,12260476416616,69868714030792,398172491295656,2269109338791176
%N Number of 2 X n 0..2 arrays x(i,j) with each element horizontally, diagonally or antidiagonally next to at least one element with value (x(i,j)+1) mod 3 and at least one element with value (x(i,j)-1) mod 3, and upper left element zero.
%H R. H. Hardin, <a href="/A231081/b231081.txt">Table of n, a(n) for n = 1..210</a>
%F Empirical: a(n) = 3*a(n-1) + 12*a(n-2) + 30*a(n-3) - 64*a(n-4) + 16*a(n-5).
%F Empirical g.f.: x*2*(1 + 4*x - 13*x^2 + 4*x^3) / (1 - 3*x - 12*x^2 - 30*x^3 + 64*x^4 - 16*x^5). - _Colin Barker_, Sep 26 2018
%e Some solutions for n=3:
%e ..0..1..0....0..3..0....0..3..2....0..3..2....0..3..0....0..1..2....0..3..2
%e ..0..3..2....2..1..0....2..1..2....0..1..0....2..1..2....0..3..0....2..1..0
%Y Row 2 of A231080.
%K nonn
%O 1,2
%A _R. H. Hardin_, Nov 03 2013
|
