A197396 Number of nX3 0..4 arrays with each element x equal to the number its horizontal and vertical neighbors equal to 3,3,1,1,1 for x=0,1,2,3,4

1, 9, 17, 81, 257, 1003, 3417, 12673, 46165, 168569, 614795, 2245461, 8191537, 29913649, 109228305, 398768515, 1455927145, 5315748449, 19407950069, 70859924513, 258716449075, 944591935629, 3448776039137, 12591745130321

Offset

1,2

Comments

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

Column 3 of A197401

Links

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

Formula

Empirical: a(n) = a(n-1) +2*a(n-2) +8*a(n-3) +50*a(n-4) +65*a(n-5) +125*a(n-6) -4*a(n-7) -330*a(n-8) -596*a(n-9) -2336*a(n-10) -1872*a(n-11) +712*a(n-12) +520*a(n-13) +4176*a(n-14) +4400*a(n-15) -1728*a(n-16) -384*a(n-17)

Example

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

Crossrefs

Sequence in context: A193663 A166705 A116526 * A015443 A253212 A217965

Adjacent sequences: A197393 A197394 A197395 * A197397 A197398 A197399

Keyword

nonn

Author

R. H. Hardin Oct 14 2011

Status

approved