A240889 Number of nX4 0..2 arrays with no element equal to a different number of vertical neighbors than horizontal neighbors, with new values 0..2 introduced in row major order

4, 36, 289, 2362, 19065, 154858, 1255585, 10186158, 82615013, 670126562, 5435464261, 44088312610, 357608156789, 2900631278142, 23527575671521, 190836751334954, 1547913820098569, 12555429390762018, 101839521640750945

Offset

1,1

Comments

Column 4 of A240893

Links

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

Formula

Empirical: a(n) = 8*a(n-1) +9*a(n-2) -63*a(n-3) +36*a(n-4) -405*a(n-5) -608*a(n-6) +600*a(n-7) +424*a(n-8) +4600*a(n-9) +10176*a(n-10) +9216*a(n-11) -2560*a(n-12) -29312*a(n-13) -40448*a(n-14) -30720*a(n-15) -16384*a(n-16)

Example

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

Crossrefs

Sequence in context: A180170 A277174 A059416 * A108019 A241104 A361554

Adjacent sequences: A240886 A240887 A240888 * A240890 A240891 A240892

Keyword

nonn

Author

R. H. Hardin, Apr 14 2014

Status

approved