A190031 Number of (n+2) X 9 binary arrays with every 3 X 3 subblock commuting with each horizontal and vertical neighbor 3 X 3 subblock.

1205, 355, 506, 790, 1162, 1494, 1910, 2362, 3002, 4006, 5390, 7234, 9790, 13178, 17955, 24448, 33157, 45099, 61313, 83131, 112959, 153552, 208458, 283316, 385153, 523121, 710869, 966189, 1312546, 1783541, 2423945, 3293354, 4475149, 6081673

Offset

1,1

Comments

Column 7 of A190033.

Links

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

Formula

Empirical: a(n) = 2*a(n-1) -a(n-2) +a(n-3) -2*a(n-4) +a(n-5) +a(n-6) -a(n-7) for n>15.

Empirical g.f.: x*(1205 - 2055*x + 1001*x^2 - 1072*x^3 + 2143*x^4 - 1041*x^5 - 1254*x^6 + 798*x^7 + 77*x^8 - 4*x^9 - 28*x^10 - 60*x^11 - 68*x^12 + 289*x^14) / ((1 - x)*(1 - x - x^3 + x^4 - x^6)). - Colin Barker, May 03 2018

Example

Some solutions for 4 X 9:
..0..0..0..0..0..0..0..1..0....0..0..0..0..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
..1..0..0..0..0..0..0..0..0....1..0..0..0..0..0..0..0..0

Crossrefs

Cf. A190033.

Sequence in context: A230838 A210015 A259521 * A254694 A279983 A187862

Adjacent sequences: A190028 A190029 A190030 * A190032 A190033 A190034

Keyword

nonn

Author

R. H. Hardin, May 04 2011

Status

approved