A221934 Number of n X 4 arrays of occupancy after each element stays put or moves to some horizontal or antidiagonal neighbor, without move-in move-out straight through or left turns.

13, 783, 36467, 1759041, 84547866, 4065176472, 195452177326, 9397301189681, 451820171352622, 21723415149940892, 1044457051240660759, 50217266705524767168, 2414435205611270005630, 116085516886164224493024

Offset

1,1

Comments

Column 4 of A221937.

Links

R. H. Hardin, Table of n, a(n) for n = 1..157

Formula

Empirical: a(n) = 45*a(n-1) +166*a(n-2) -812*a(n-3) -2452*a(n-4) +2243*a(n-5) +23138*a(n-6) +2192*a(n-7) +908*a(n-8) +6885*a(n-9) -5028*a(n-10) +3940*a(n-11) -628*a(n-12) +36*a(n-13).

Example

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

Crossrefs

Cf. A221937.

Sequence in context: A262099 A301644 A182932 * A328033 A366559 A316673

Adjacent sequences: A221931 A221932 A221933 * A221935 A221936 A221937

Keyword

nonn

Author

R. H. Hardin, Feb 01 2013

Status

approved