A197643 Number of nX3 0..4 arrays with each element x equal to the number its horizontal and vertical neighbors equal to 4,2,2,0,2 for x=0,1,2,3,4

1, 11, 82, 342, 1649, 9007, 49381, 256485, 1303838, 6775152, 35730226, 187160271, 972480937, 5058363340, 26414032504, 137991741860, 719704308772, 3751431869467, 19565984801032, 102090380933252, 532589325917487

Offset

1,2

Comments

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

Column 3 of A197648

Links

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

Formula

Empirical: a(n) = 3*a(n-1) +22*a(n-3) +162*a(n-4) +207*a(n-5) +40*a(n-6) -199*a(n-7) -964*a(n-8) -1725*a(n-9) -4618*a(n-10) +565*a(n-11) +1265*a(n-12) +854*a(n-13) -504*a(n-14) +24*a(n-15)

Example

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

Crossrefs

Sequence in context: A111334 A085879 A239459 * A261391 A211845 A029887

Adjacent sequences: A197640 A197641 A197642 * A197644 A197645 A197646

Keyword

nonn

Author

R. H. Hardin Oct 16 2011

Status

approved