A200796 Number of nX3 0..3 arrays with values 0..3 introduced in row major order and each element equal to no more than two horizontal and vertical neighbors

5, 178, 9880, 583813, 34679839, 2060918000, 122478253815, 7278777317468, 432571571252989, 25707362563355693, 1527766813187552208, 90793889493222901029, 5395804057415427972197, 320668071260622898796015

Offset

1,1

Comments

Column 3 of A200801

Links

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

Formula

Empirical: a(n) = 60*a(n-1) -17*a(n-2) -964*a(n-3) -2509*a(n-4) +968*a(n-5) +23125*a(n-6) +31652*a(n-7) -4566*a(n-8) -17118*a(n-9) -29646*a(n-10) -74826*a(n-11) -64125*a(n-12) -13932*a(n-13) +4131*a(n-14) +1458*a(n-15) for n>16

Example

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

Crossrefs

Sequence in context: A111515 A157204 A248383 * A241115 A208196 A194571

Adjacent sequences: A200793 A200794 A200795 * A200797 A200798 A200799

Keyword

nonn

Author

R. H. Hardin Nov 22 2011

Status

approved