cp's OEIS Frontend

A221695 Number of 3Xn arrays of occupancy after each element stays put or moves to some horizontal or antidiagonal neighbor, without consecutive moves in the same direction.

%I A221695 #6 Jul 23 2025 02:07:31
%S A221695 1,144,3112,95076,2627760,74531185,2098932856,59210733473,
%T A221695 1669668324450,47086135048676,1327854674388881,37446255355092156,
%U A221695 1056006037475086696,29779973215497145163,839812326958816104725,23683188619380401285537
%N A221695 Number of 3Xn arrays of occupancy after each element stays put or moves to some horizontal or antidiagonal neighbor, without consecutive moves in the same direction.
%C A221695 Row 3 of A221693
%H A221695 R. H. Hardin, <a href="/A221695/b221695.txt">Table of n, a(n) for n = 1..69</a>
%e A221695 Some solutions for n=3
%e A221695 ..0..3..2....0..3..0....1..0..0....0..2..0....1..0..1....2..0..0....1..0..2
%e A221695 ..0..1..0....0..1..1....2..1..1....2..2..1....2..1..1....2..1..1....2..1..0
%e A221695 ..1..2..0....2..2..0....1..3..0....1..0..1....1..2..0....1..0..2....0..3..0
%K A221695 nonn
%O A221695 1,2
%A A221695 _R. H. Hardin_ Jan 22 2013