cp's OEIS Frontend

A221126 Number of 2 X n arrays of occupancy after each element stays put or moves to some horizontal or antidiagonal neighbor.

%I A221126 #8 Aug 04 2018 06:40:39
%S A221126 1,21,200,1950,19005,185164,1803949,17574675,171218008,1668058947,
%T A221126 16250746331,158319795778,1542400400537,15026541578483,
%U A221126 146393213915408,1426207951308175,13894558811577567,135365087812821450
%N A221126 Number of 2 X n arrays of occupancy after each element stays put or moves to some horizontal or antidiagonal neighbor.
%C A221126 Row 2 of A221125.
%H A221126 R. H. Hardin, <a href="/A221126/b221126.txt">Table of n, a(n) for n = 1..88</a>
%F A221126 Empirical: a(n) = 11*a(n-1) - 11*a(n-2) - 12*a(n-3) - 2*a(n-4) for n>6.
%F A221126 Empirical g.f.: x*(1 + 10*x - 20*x^2 - 7*x^3 + 9*x^4 + x^5) / (1 - 11*x + 11*x^2 + 12*x^3 + 2*x^4). - _Colin Barker_, Aug 04 2018
%e A221126 Some solutions for n=3:
%e A221126 ..0..1..0....1..0..2....1..2..0....1..2..0....0..3..1....1..1..1....0..1..0
%e A221126 ..2..3..0....0..1..2....2..0..1....1..2..0....0..0..2....1..0..2....2..1..2
%Y A221126 Cf. A221125.
%K A221126 nonn
%O A221126 1,2
%A A221126 _R. H. Hardin_, Jan 02 2013