cp's OEIS Frontend

A221933 Number of n X 3 arrays of occupancy after each element stays put or moves to some horizontal or antidiagonal neighbor, without move-in move-out straight through or left turns.

%I A221933 #9 Aug 11 2018 13:10:11
%S A221933 6,105,1599,24535,376389,5773962,88575493,1358791848,20844539836,
%T A221933 319765562424,4905362062396,75250682972713,1154382737872290,
%U A221933 17708802802243865,271661803663808763,4167426584055854255
%N A221933 Number of n X 3 arrays of occupancy after each element stays put or moves to some horizontal or antidiagonal neighbor, without move-in move-out straight through or left turns.
%C A221933 Column 3 of A221937.
%H A221933 R. H. Hardin, <a href="/A221933/b221933.txt">Table of n, a(n) for n = 1..210</a>
%F A221933 Empirical: a(n) = 14*a(n-1) + 21*a(n-2) - 5*a(n-3) - 26*a(n-4) + a(n-5).
%F A221933 Empirical g.f.: x*(6 + 21*x + 3*x^2 - 26*x^3 + x^4) / (1 - 14*x - 21*x^2 + 5*x^3 + 26*x^4 - x^5). - _Colin Barker_, Aug 11 2018
%e A221933 Some solutions for n=3:
%e A221933 ..0..3..1....1..3..0....2..0..1....1..0..1....2..0..1....1..2..0....0..2..1
%e A221933 ..0..1..0....0..2..0....1..0..1....2..1..0....2..0..0....0..3..0....0..4..0
%e A221933 ..0..3..1....1..2..0....2..2..0....1..3..0....1..2..1....1..0..2....1..0..1
%Y A221933 Cf. A221937.
%K A221933 nonn
%O A221933 1,1
%A A221933 _R. H. Hardin_, Feb 01 2013