A237465 Number of (n+1) X (1+1) 0..2 arrays with the maximum plus the lower median minus the upper median of every 2 X 2 subblock differing from its horizontal and vertical neighbors by exactly one.

81, 356, 1566, 6954, 30913, 136488, 603184, 2671904, 11847888, 52383008, 231824656, 1026098208, 4546286096, 20109616256, 89038511104, 393995791360, 1745176506880, 7720658462720, 34190008144896, 151276942817792

Offset

1,1

Links

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

Formula

Empirical: a(n) = 288*a(n-4) + 1840*a(n-6) + 784*a(n-8).

Empirical g.f.: x*(81 + 356*x + 1566*x^2 + 6954*x^3 + 7585*x^4 + 33960*x^5 + 3136*x^6 + 14112*x^7) / (1 - 288*x^4 - 1840*x^6 - 784*x^8). - Colin Barker, Oct 22 2018

Example

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

Crossrefs

Column 1 of A237472.

Sequence in context: A237317 A237723 A237472 * A236997 A236065 A206676

Adjacent sequences: A237462 A237463 A237464 * A237466 A237467 A237468

Keyword

nonn

Author

R. H. Hardin, Feb 08 2014

Status

approved