cp's OEIS Frontend

A221780 T(n,k)=Number of nXk arrays of occupancy after each element stays put or moves to some horizontal, diagonal or antidiagonal neighbor, without move-in move-out left turns.

%I A221780 #6 Jul 23 2025 02:12:28
%S A221780 1,3,1,8,25,1,21,258,184,1,55,2631,7676,1367,1,144,26861,311500,
%T A221780 230621,10179,1,377,273816,12449782,36959565,6911480,75782,1,987,
%U A221780 2792384,496125037,5758151603,4383899151,207263892,564169,1,2584,28476902
%N A221780 T(n,k)=Number of nXk arrays of occupancy after each element stays put or moves to some horizontal, diagonal or antidiagonal neighbor, without move-in move-out left turns.
%C A221780 Table starts
%C A221780 .1.......3..........8...........21............55..........144.........377
%C A221780 .1......25........258.........2631.........26861.......273816.....2792384
%C A221780 .1.....184.......7676.......311500......12449782....496125037.19763197787
%C A221780 .1....1367.....230621.....36959565....5758151603.889201607649
%C A221780 .1...10179....6911480...4383899151.2659707427087
%C A221780 .1...75782..207263892.519828193272
%C A221780 .1..564169.6215606652
%C A221780 .1.4200043
%C A221780 .1
%H A221780 R. H. Hardin, <a href="/A221780/b221780.txt">Table of n, a(n) for n = 1..48</a>
%e A221780 Some solutions for n=3 k=4
%e A221780 ..0..3..0..1....0..2..3..1....0..1..1..3....0..2..1..0....0..0..0..0
%e A221780 ..0..2..3..1....0..2..1..0....1..0..2..0....0..0..4..0....1..4..3..1
%e A221780 ..0..1..0..1....2..0..0..1....1..0..3..0....1..2..0..2....0..0..1..2
%Y A221780 Row 1 is A001906
%K A221780 nonn,tabl
%O A221780 1,2
%A A221780 _R. H. Hardin_ Jan 25 2013