A197471 Number of nX4 0..4 arrays with each element x equal to the number its horizontal and vertical neighbors equal to 0,1,0,0,0 for x=0,1,2,3,4

1, 12, 46, 184, 748, 2824, 10934, 42474, 164782, 638460, 2473902, 9589038, 37167908, 144059050, 558354234, 2164121964, 8387927204, 32510787510, 126008566828, 488396574430, 1892976376006, 7336987712088, 28437432700816, 110220652223106

Offset

1,2

Comments

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

Column 4 of A197475

Links

R. H. Hardin, Table of n, a(n) for n = 1..210

Formula

Empirical: a(n) = a(n-1) +5*a(n-2) +19*a(n-3) +15*a(n-4) +24*a(n-5) -17*a(n-6) -55*a(n-7) -114*a(n-8) +5*a(n-9) +182*a(n-10) +372*a(n-11) +28*a(n-12) -230*a(n-13) -289*a(n-14) -284*a(n-15) -44*a(n-16) +101*a(n-17) +174*a(n-18) -28*a(n-19) +80*a(n-20) +8*a(n-21) -8*a(n-22) +144*a(n-23) -48*a(n-25) for n>28

Example

Some solutions containing all values 0 to 4 for n=5
..2..0..3..0....1..2..0..2....0..3..0..1....0..3..0..2....0..2..0..2
..0..4..0..3....1..0..4..0....3..0..3..1....2..0..4..0....1..1..2..0
..2..0..1..0....0..1..0..3....0..4..0..2....1..1..0..2....2..0..2..1
..1..2..1..2....2..1..3..0....3..0..3..0....0..2..1..1....0..4..0..1
..1..0..2..0....0..2..0..2....0..2..1..1....2..0..2..0....2..0..3..0

Crossrefs

Sequence in context: A050490 A169881 A200669 * A159013 A022281 A244803

Adjacent sequences: A197468 A197469 A197470 * A197472 A197473 A197474

Keyword

nonn

Author

R. H. Hardin Oct 15 2011

Status

approved