A197674 Number of nX3 0..4 arrays with each element x equal to the number its horizontal and vertical neighbors equal to 2,0,1,0,1 for x=0,1,2,3,4

4, 16, 57, 202, 721, 2557, 8930, 31326, 110217, 387627, 1363559, 4796483, 16870356, 59337438, 208705786, 734075168, 2581952574, 9081465807, 31942103268, 112349483389, 395165129695, 1389908311471, 4888703531124, 17194963235219

Offset

1,1

Comments

Every 0 is next to 0 2's, every 1 is next to 1 0's, every 2 is next to 2 1's, every 3 is next to 3 0's, every 4 is next to 4 1's

Column 3 of A197679

Links

R. H. Hardin, Table of n, a(n) for n = 1..200

Formula

Empirical: a(n) = 4*a(n-1) +a(n-2) -6*a(n-3) -14*a(n-4) +29*a(n-6) -18*a(n-7) -29*a(n-8) -46*a(n-9) +79*a(n-10) +199*a(n-11) +62*a(n-12) -91*a(n-13) -228*a(n-14) -70*a(n-15) +92*a(n-16) +71*a(n-17) +30*a(n-18) -35*a(n-19) -3*a(n-20) -3*a(n-21) -18*a(n-22) +4*a(n-23) +a(n-24) -a(n-25) +a(n-26)

Example

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

Crossrefs

Sequence in context: A220106 A281064 A122032 * A297220 A297375 A283124

Adjacent sequences: A197671 A197672 A197673 * A197675 A197676 A197677

Keyword

nonn

Author

R. H. Hardin Oct 17 2011

Status

approved