cp's OEIS Frontend

A221850 Number of nX3 arrays of occupancy after each element stays put or moves to some horizontal, diagonal or antidiagonal neighbor, without consecutive moves in the same direction.

%I A221850 #7 Jul 23 2025 02:16:58
%S A221850 6,302,10085,354670,12277568,426752551,14818941152,514719294830,
%T A221850 17877010521736,620906972675376,21565339027443844,749008098922831183,
%U A221850 26014567709115430632,903538668696429777028,31381728865914983789375
%N A221850 Number of nX3 arrays of occupancy after each element stays put or moves to some horizontal, diagonal or antidiagonal neighbor, without consecutive moves in the same direction.
%C A221850 Column 3 of A221852
%H A221850 R. H. Hardin, <a href="/A221850/b221850.txt">Table of n, a(n) for n = 1..27</a>
%e A221850 Some solutions for n=3
%e A221850 ..1..0..1....0..2..0....1..1..0....1..1..2....0..1..2....0..1..1....1..0..1
%e A221850 ..0..0..1....1..0..0....1..6..0....2..0..0....0..3..0....1..0..1....0..0..1
%e A221850 ..1..2..3....3..2..1....0..0..0....0..1..2....2..0..1....2..1..2....0..4..2
%K A221850 nonn
%O A221850 1,1
%A A221850 _R. H. Hardin_ Jan 27 2013