cp's OEIS Frontend

A221001 T(n,k)=Number of nXk arrays of occupancy after each element stays put or moves to some horizontal or vertical neighbor.

%I A221001 #6 Jul 23 2025 01:37:06
%S A221001 1,3,3,8,31,8,21,306,306,21,55,2989,11017,2989,55,144,29135,394580,
%T A221001 394580,29135,144,377,283872,14113081,51672851,14113081,283872,377,
%U A221001 987,2765627,504635391,6758547145,6758547145,504635391,2765627,987,2584
%N A221001 T(n,k)=Number of nXk arrays of occupancy after each element stays put or moves to some horizontal or vertical neighbor.
%C A221001 Table starts
%C A221001 ....1.........3............8..............21...............55..............144
%C A221001 ....3........31..........306............2989............29135...........283872
%C A221001 ....8.......306........11017..........394580.........14113081........504635391
%C A221001 ...21......2989.......394580........51672851.......6758547145.....883809591160
%C A221001 ...55.....29135.....14113081......6758547145....3229188933738.1542208831960569
%C A221001 ..144....283872....504635391....883809591160.1542208831960569
%C A221001 ..377...2765627..18042682111.115571009291599
%C A221001 ..987..26943707.645084293748
%C A221001 .2584.262494146
%C A221001 .6765
%H A221001 R. H. Hardin, <a href="/A221001/b221001.txt">Table of n, a(n) for n = 1..60</a>
%e A221001 Some solutions for n=3 k=4
%e A221001 ..0..0..1..0....0..1..2..0....0..0..1..0....0..1..0..0....0..0..4..1
%e A221001 ..2..1..0..1....2..2..0..0....2..2..1..1....1..2..2..4....2..2..0..1
%e A221001 ..1..2..1..3....0..2..0..3....1..0..4..0....1..0..1..0....1..0..0..1
%Y A221001 Column 1 is A001906
%K A221001 nonn,tabl
%O A221001 1,2
%A A221001 _R. H. Hardin_ Dec 28 2012