A237456 Number of (n+1) X (1+1) 0..2 arrays with the maximum plus the lower median of every 2 X 2 subblock differing from its horizontal and vertical neighbors by exactly one.

81, 308, 1144, 4272, 16280, 61152, 231680, 869120, 3299584, 12382208, 46966784, 176229376, 668720640, 2509305856, 9520095232, 35722403840, 135538946048, 508589948928, 1929634152448, 7240635777024, 27472062906368, 103084621299712

Offset

1,1

Links

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

Formula

Empirical: a(n) = 136*a(n-4) + 832*a(n-6) + 1600*a(n-8) + 1024*a(n-10).

Empirical g.f.: x*(81 + 308*x + 1144*x^2 + 4272*x^3 + 5264*x^4 + 19264*x^5 + 8704*x^6 + 31872*x^7 + 4096*x^8 + 18432*x^9) / (1 - 136*x^4 - 832*x^6 - 1600*x^8 - 1024*x^10). - Colin Barker, Oct 22 2018

Example

Some solutions for n=5:
..1..0....1..0....1..1....2..2....2..1....2..0....1..1....0..0....2..1....2..1
..0..0....1..0....1..0....1..1....2..0....1..1....1..0....1..2....0..0....2..0
..2..1....0..2....2..2....1..0....2..0....1..0....1..0....1..1....0..1....2..2
..0..2....1..1....2..1....0..0....1..2....0..0....0..2....0..1....1..1....1..1
..1..0....0..1....1..1....2..1....0..0....1..2....2..1....1..0....0..2....1..1
..0..0....0..0....0..1....1..2....1..0....1..1....2..2....0..2....0..0....1..2

Crossrefs

Column 1 of A237463.

Sequence in context: A236011 A206678 A237463 * A183994 A237703 A237696

Adjacent sequences: A237453 A237454 A237455 * A237457 A237458 A237459

Keyword

nonn

Author

R. H. Hardin, Feb 08 2014

Status

approved