A221656 Number of 2Xn arrays of occupancy after each element moves to some horizontal, diagonal or antidiagonal neighbor, without move-in move-out left turns

0, 4, 24, 165, 1054, 6862, 44576, 289789, 1883406, 12241008, 79558150, 517073937, 3360625086, 21841749571, 141956320765, 922618247832, 5996382690315, 38972354390400, 253293441134093, 1646232780191728, 10699378374870619

Offset

1,2

Comments

Row 2 of A221655

Links

R. H. Hardin, Table of n, a(n) for n = 1..180

Formula

Empirical: a(n) = 9*a(n-1) -15*a(n-2) -15*a(n-3) +52*a(n-4) -51*a(n-5) -a(n-6) +127*a(n-7) -32*a(n-8) -28*a(n-9) +25*a(n-10) for n>12

Example

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

Crossrefs

Sequence in context: A027079 A213441 A238299 * A366623 A339346 A214377

Adjacent sequences: A221653 A221654 A221655 * A221657 A221658 A221659

Keyword

nonn

Author

R. H. Hardin Jan 21 2013

Status

approved