A221828 T(n,k)=Number of nXk arrays of occupancy after each element moves to some horizontal, vertical or antidiagonal neighbor, without 2-loops or left turns.

0, 0, 0, 0, 3, 0, 0, 16, 14, 0, 0, 73, 202, 64, 0, 0, 333, 2879, 2930, 292, 0, 0, 1519, 40983, 115417, 41618, 1332, 0, 0, 6929, 583419, 4715043, 4755445, 592601, 6076, 0, 0, 31607, 8304016, 192788993, 570066685, 194407111, 8434490, 27716, 0, 0, 144177

Offset: 1

Author

R. H. Hardin Jan 26 2013

Keywords

• nonn
• tabl

Comments

Table starts

.0......0..........0............0.............0..............0.............0

.0......3.........16...........73...........333...........1519..........6929

.0.....14........202.........2879.........40983.........583419.......8304016

.0.....64.......2930.......115417.......4715043......192788993....7888216533

.0....292......41618......4755445.....570066685....68573607669.8233561918895

.0...1332.....592601....194407111...68489860450.24121109763712

.0...6076....8434490...7954432829.8224749361083

.0..27716..120053263.325446165881

.0.126428.1708776751

.0.576708

.0

Examples

			Some solutions for n=3 k=4
..0..1..1..0....1..2..1..1....1..1..0..2....0..2..0..1....1..1..1..1
..1..2..0..1....1..1..2..1....2..1..1..1....2..1..0..1....1..0..1..2
..2..1..2..1....0..0..1..1....1..1..1..0....1..2..1..1....1..1..2..0
		

Links

• R. H. Hardin, Table of n, a(n) for n = 1..71

Crossrefs

Column 2 is A060801(n-1)

Formula

Empirical for col 2: a(n) = 5*a(n-1) -2*a(n-2) for n>3

Empirical for row 2: a(k)=5*a(k-1)-2*a(k-2) for k>4