A206260 Number of (n+1) X 2 0..1 arrays with the number of rightwards and downwards edge increases in each 2 X 2 subblock equal to the number in all its horizontal and vertical neighbors.

16, 24, 34, 50, 72, 105, 154, 229, 345, 527, 815, 1274, 2009, 3190, 5092, 8160, 13114, 21119, 34060, 54987, 88835, 143589, 232169, 375480, 607347, 982500, 1589494, 2571614, 4160700, 6731877, 10892110, 17623489, 28515069, 46137995, 74652467

Offset

1,1

Comments

Column 1 of A206267.

Links

R. H. Hardin, Table of n, a(n) for n = 1..210

Formula

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

Empirical g.f.: x*(16 - 40*x + 18*x^2 + 18*x^3 - 14*x^4 + x^5) / ((1 - x)^3*(1 - x - x^2)). - Colin Barker, Jun 14 2018

Example

Some solutions for n=4:
..0..0....0..1....0..1....1..1....1..0....1..1....0..0....1..1....0..0....1..0
..0..1....1..0....1..0....0..0....0..0....1..1....1..0....1..0....0..0....1..1
..1..0....0..1....0..1....0..0....0..0....1..1....1..1....0..0....0..0....0..1
..0..1....1..0....0..1....0..0....0..0....1..0....0..1....0..0....0..0....0..0
..1..0....0..1....1..0....0..0....0..0....1..0....0..0....0..0....0..0....1..0

Crossrefs

Cf. A206267.

Sequence in context: A273801 A163284 A100316 * A036328 A067028 A110893

Adjacent sequences: A206257 A206258 A206259 * A206261 A206262 A206263

Keyword

nonn

Author

R. H. Hardin, Feb 05 2012

Status

approved