A208875 Number of 4Xn 0..3 arrays with new values 0..3 introduced in row major order and no element equal to more than one of its immediate leftward or upward or right-upward antidiagonal neighbors.

15, 1979, 324682, 52947540, 8624977114, 1404920207834, 228847686794351, 37277070892199501, 6072074518379364073, 989082262060956074133, 161111942886719306980432, 26243578660069203997974518

Offset

1,1

Comments

Row 4 of A208872

Links

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

Formula

Empirical: a(n) = 222*a(n-1) -10949*a(n-2) +228692*a(n-3) -2273610*a(n-4) +10170544*a(n-5) -13839646*a(n-6) -45418980*a(n-7) +225253855*a(n-8) -439046430*a(n-9) +509809347*a(n-10) -407061936*a(n-11) +239595084*a(n-12) -96068592*a(n-13) +18662400*a(n-14) for n>16

Example

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

Crossrefs

Sequence in context: A232305 A282946 A319623 * A199098 A208784 A126681

Adjacent sequences: A208872 A208873 A208874 * A208876 A208877 A208878

Keyword

nonn

Author

R. H. Hardin, Mar 02 2012

Status

approved