A221548 Number of nX2 arrays of occupancy after each element moves to some horizontal, vertical or antidiagonal neighbor, without move-in move-out left turns

1, 10, 71, 494, 3448, 24055, 167811, 1170709, 8167235, 56977308, 397492341, 2773036806, 19345613394, 134961338332, 941534521444, 6568453351718, 45823682988617, 319681028423436, 2230199610078620, 15558603290655476

Offset

1,2

Comments

Column 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....1..1....0..1....0..1....1..1....1..1....0..2....0..1....0..2....0..1
..0..1....2..1....1..1....2..1....2..0....0..2....1..0....1..1....3..0....2..2
..1..2....0..1....2..1....2..0....2..0....2..0....1..2....3..0....1..0....1..0

Crossrefs

Sequence in context: A016098 A129275 A049672 * A037579 A166791 A271035

Adjacent sequences: A221545 A221546 A221547 * A221549 A221550 A221551

Keyword

nonn

Author

R. H. Hardin Jan 19 2013

Status

approved