A186582 Number of (n+3) X 5 0..2 arrays with every 4 X 4 subblock commuting with each horizontal and vertical neighbor 4 X 4 subblock.

8824, 827, 1991, 12263, 42313, 79015, 98893, 104983, 108805, 112735, 118765, 143799, 230021, 395695, 605325, 865143, 1254981, 1811583, 2468157, 3275175, 4514677, 6419055, 8942637, 12286743, 17275493, 24707199, 34690461, 47928807

Offset

1,1

Comments

Column 2 of A186589.

Links

R. H. Hardin, Table of n, a(n) for n = 1..200

Formula

Empirical: a(n) = 2*a(n-1) - a(n-2) + 2*a(n-4) - 4*a(n-5) + 2*a(n-6) + 2*a(n-8) - 2*a(n-9) for n>14.

Empirical g.f.: x*(8824 - 16821*x + 9161*x^2 + 9108*x^3 + 2130*x^4 + 40294*x^5 - 35146*x^6 - 32004*x^7 - 59472*x^8 + 2798*x^9 + 33420*x^10 + 26036*x^11 + 5624*x^12 + 5832*x^13) / ((1 - x)*(1 - x - 2*x^4 + 2*x^5 - 2*x^8)). - Colin Barker, Apr 18 2018

Example

Some solutions for 7 X 5:
..0..0..0..1..2....0..0..0..0..0....0..0..2..2..2....0..0..2..2..2
..0..0..0..0..0....0..0..0..0..0....0..0..0..0..1....0..0..0..0..1
..0..0..0..0..0....0..0..0..0..0....0..0..0..0..0....0..0..0..0..0
..0..0..0..0..0....0..0..0..0..0....0..0..0..0..0....0..0..0..0..0
..0..0..0..0..0....0..0..0..0..0....0..0..0..0..0....0..0..0..0..0
..0..0..0..0..0....0..0..0..0..0....2..0..0..0..0....1..0..0..0..0
..1..2..2..0..0....1..2..1..0..0....2..0..2..0..0....1..0..0..0..0

Crossrefs

Cf. A186589.

Sequence in context: A183752 A109027 A237761 * A147529 A255089 A255078

Adjacent sequences: A186579 A186580 A186581 * A186583 A186584 A186585

Keyword

nonn

Author

R. H. Hardin, Feb 24 2011

Status

approved