A186581 Number of (n+3) X 4 0..2 arrays with every 4 X 4 subblock commuting with each horizontal and vertical neighbor 4 X 4 subblock.

43046721, 8824, 38608, 192026, 805791, 1728546, 2296065, 2604716, 2927679, 3089510, 3313917, 4090548, 6218902, 9961241, 15014753, 21788652, 31911831, 45586648, 62332637, 84072672, 116767981, 164051247, 227583882, 314652408

Offset

1,1

Comments

Column 1 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>24.

Example

Some solutions for 5 X 4
..0..1..1..0....1..1..1..2....1..0..0..1....2..0..1..0....1..1..1..0
..0..0..1..1....0..1..1..2....0..1..0..2....0..2..1..0....0..1..1..0
..2..0..0..0....0..0..1..1....0..0..1..0....0..2..1..0....0..0..1..0
..0..2..0..0....0..0..0..0....0..0..0..0....0..2..1..0....0..0..0..0
..0..0..2..0....0..0..0..0....0..0..0..0....0..0..1..2....0..0..0..1

Crossrefs

Cf. A186589.

Sequence in context: A288843 A186580 A186589 * A017084 A017168 A017384

Adjacent sequences: A186578 A186579 A186580 * A186582 A186583 A186584

Keyword

nonn

Author

R. H. Hardin, Feb 24 2011

Status

approved