A220939 Number of n X 2 arrays of occupancy after each element moves to some horizontal, vertical or antidiagonal neighbor.

1, 20, 208, 2056, 20483, 203905, 2029453, 20199560, 201050056, 2001087460, 19917184799, 198239333473, 1973111833705, 19638737859212, 195467898964096, 1945527242870032, 19364183442340907, 192735209316410785

Offset

1,2

Comments

Column 2 of A220943.

Links

R. H. Hardin, Table of n, a(n) for n = 1..83

Formula

Empirical: a(n) = 13*a(n-1) - 32*a(n-2) + 22*a(n-3) - 62*a(n-4) + 92*a(n-5) - 33*a(n-6) + a(n-7).

Empirical g.f.: x*(1 + 7*x - 20*x^2 - 30*x^3 + 33*x^4 - 10*x^5 + x^6) / ((1 - x)*(1 - 12*x + 20*x^2 - 2*x^3 + 60*x^4 - 32*x^5 + x^6)). - Colin Barker, Aug 03 2018

Example

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

Crossrefs

Cf. A220943.

Sequence in context: A364651 A133070 A135179 * A231059 A161513 A162359

Adjacent sequences: A220936 A220937 A220938 * A220940 A220941 A220942

Keyword

nonn

Author

R. H. Hardin, Dec 25 2012

Status

approved