cp's OEIS Frontend

A221937 T(n,k)=Number of nXk arrays of occupancy after each element stays put or moves to some horizontal or antidiagonal neighbor, without move-in move-out straight through or left turns.

%I A221937 #6 Jul 23 2025 02:21:09
%S A221937 1,3,1,6,17,1,13,105,91,1,28,783,1599,489,1,60,5622,36467,24535,2627,
%T A221937 1,129,40608,799632,1759041,376389,14113,1,277,293084,17595404,
%U A221937 119035112,84547866,5773962,75819,1,595,2115379,387146025,8118923949,17626884659
%N A221937 T(n,k)=Number of nXk arrays of occupancy after each element stays put or moves to some horizontal or antidiagonal neighbor, without move-in move-out straight through or left turns.
%C A221937 Table starts
%C A221937 .1........3...........6............13..............28...............60
%C A221937 .1.......17.........105...........783............5622............40608
%C A221937 .1.......91........1599.........36467..........799632.........17595404
%C A221937 .1......489.......24535.......1759041.......119035112.......8118923949
%C A221937 .1.....2627......376389......84547866.....17626884659....3719159201319
%C A221937 .1....14113.....5773962....4065176472...2611330803361.1705064784016177
%C A221937 .1....75819....88575493..195452177326.386840503637732
%C A221937 .1...407321..1358791848.9397301189681
%C A221937 .1..2188243.20844539836
%C A221937 .1.11755857
%C A221937 .1
%H A221937 R. H. Hardin, <a href="/A221937/b221937.txt">Table of n, a(n) for n = 1..71</a>
%e A221937 Some solutions for n=3 k=4
%e A221937 ..1..1..1..1....0..3..0..1....0..2..3..0....1..1..2..1....1..2..0..1
%e A221937 ..1..1..3..1....1..1..2..1....1..0..0..2....1..0..2..0....0..1..2..1
%e A221937 ..0..0..2..0....1..0..2..0....0..2..2..0....1..2..0..1....2..0..0..2
%Y A221937 Column 2 is A221731
%Y A221937 Row 1 is A002478
%K A221937 nonn,tabl
%O A221937 1,2
%A A221937 _R. H. Hardin_ Feb 01 2013