cp's OEIS Frontend

A221728 T(n,k)=Number of nXk arrays of occupancy after each element stays put or moves to some horizontal, diagonal or antidiagonal neighbor, with every occupancy equal to zero or two.

%I A221728 #6 Jul 23 2025 02:08:21
%S A221728 0,2,0,0,6,0,4,16,16,0,0,52,0,44,0,8,174,540,464,120,0,0,588,0,6188,0,
%T A221728 328,0,16,1984,22180,80160,71310,13948,896,0,0,6688,0,1048566,0,
%U A221728 824144,0,2448,0,32,22536,911081,13757056,47798542,42509454,9525048,420736,6688,0
%N A221728 T(n,k)=Number of nXk arrays of occupancy after each element stays put or moves to some horizontal, diagonal or antidiagonal neighbor, with every occupancy equal to zero or two.
%C A221728 Table starts
%C A221728 .0....2......0.......4........0........8........0........16.....0....32.0
%C A221728 .0....6.....16......52......174......588.....1984......6688.22536.75924
%C A221728 .0...16......0.....540........0....22180........0....911081.....0
%C A221728 .0...44....464....6188....80160..1048566.13757056.180437354
%C A221728 .0..120......0...71310........0.47798542
%C A221728 .0..328..13948..824144.42509454
%C A221728 .0..896......0.9525048
%C A221728 .0.2448.420736
%C A221728 .0.6688
%C A221728 .0
%H A221728 R. H. Hardin, <a href="/A221728/b221728.txt">Table of n, a(n) for n = 1..59</a>
%e A221728 Some solutions for n=3 k=4
%e A221728 ..2..0..2..0....0..2..0..0....0..2..0..0....2..0..0..2....2..0..0..2
%e A221728 ..0..2..2..0....2..0..2..2....2..0..2..0....2..2..2..0....0..2..0..2
%e A221728 ..0..2..0..2....2..0..2..0....2..2..0..2....0..2..0..0....0..2..2..0
%Y A221728 Column 2 is A002605(n+1)
%Y A221728 Row 2 is A221270
%K A221728 nonn,tabl
%O A221728 1,2
%A A221728 _R. H. Hardin_ Jan 22 2013