A221552 Number of 2Xn arrays of occupancy after each element moves to some horizontal, vertical or antidiagonal neighbor, without move-in move-out left turns

1, 10, 72, 503, 3517, 24546, 171268, 1194876, 8335964, 58154668, 405706565, 2830343128, 19745403738, 137750412592, 960992030353, 6704195338721, 46770663635910, 326287475880302, 2276288352727268, 15880133462880199

Offset

1,2

Comments

Row 2 of A221551

Links

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

Formula

Empirical: a(n) = 11*a(n-1) -25*a(n-2) -46*a(n-3) +164*a(n-4) +129*a(n-5) -513*a(n-6) -301*a(n-7) +913*a(n-8) +562*a(n-9) -943*a(n-10) -675*a(n-11) +513*a(n-12) +436*a(n-13) -128*a(n-14) -111*a(n-15) +17*a(n-16) +6*a(n-17)

Example

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

Crossrefs

Sequence in context: A228316 A228310 A164546 * A037712 A037614 A138782

Adjacent sequences: A221549 A221550 A221551 * A221553 A221554 A221555

Keyword

nonn

Author

R. H. Hardin Jan 19 2013

Status

approved