A253461 Number of (n+1) X (n+1) 0..2 arrays with every 2 X 2 subblock diagonal maximum minus antidiagonal minimum unequal to its neighbors horizontally, vertically, diagonally and antidiagonally.

81, 800, 2000, 3744, 8000, 12800, 32000, 59904, 128000, 204800, 512000, 958464, 2048000, 3276800, 8192000, 15335424, 32768000, 52428800, 131072000, 245366784, 524288000, 838860800, 2097152000, 3925868544, 8388608000, 13421772800

Offset

1,1

Links

R. H. Hardin, Table of n, a(n) for n = 1..48

Formula

Empirical: a(n) = 16*a(n-4) for n>5.

Empirical g.f.: x*(81 + 800*x + 2000*x^2 + 3744*x^3 + 6704*x^4) / ((1 - 2*x)*(1 + 2*x)*(1 + 4*x^2)). - Colin Barker, Dec 13 2018

Example

Some solutions for n=4:
..0..0..1..0..2....0..2..1..1..2....1..2..0..2..1....2..0..2..0..2
..1..1..0..1..0....0..0..1..0..2....2..1..1..0..1....0..2..1..1..0
..1..1..2..1..2....1..1..0..1..0....1..2..0..1..1....1..1..2..0..1
..1..2..1..2..0....1..1..2..1..2....2..1..1..0..2....0..2..1..1..0
..1..0..2..2..2....1..2..1..2..1....2..2..1..0..0....2..2..1..1..1

Crossrefs

Diagonal of A253468.

Sequence in context: A206086 A356534 A224002 * A247842 A273233 A045792

Adjacent sequences: A253458 A253459 A253460 * A253462 A253463 A253464

Keyword

nonn

Author

R. H. Hardin, Jan 01 2015

Status

approved