A253465 Number of (n+1) X (4+1) 0..2 arrays with every 2 X 2 subblock diagonal maximum minus antidiagonal minimum unequal to its neighbors horizontally, vertically, diagonally and antidiagonally.

24208, 3072, 2600, 3744, 7496, 8272, 15680, 31824, 94016, 104272, 224960, 481104, 1478336, 1640272, 3573440, 7669584, 23627456, 26216272, 57149120, 122685264, 378013376, 419432272, 914360000, 1962936144, 6048188096, 6710888272

Offset

1,1

Links

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

Formula

Empirical: a(n) = a(n-2) + 16*a(n-4) - 16*a(n-6) for n>8.

Empirical g.f.: 8*x*(3026 + 384*x - 2701*x^2 + 84*x^3 - 47804*x^4 - 5578*x^5 + 44239*x^6 + 1600*x^7) / ((1 - x)*(1 + x)*(1 - 2*x)*(1 + 2*x)*(1 + 4*x^2)). - Colin Barker, Dec 14 2018

Example

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

Crossrefs

Column 4 of A253468.

Sequence in context: A234165 A321063 A309018 * A251154 A078870 A154069

Adjacent sequences: A253462 A253463 A253464 * A253466 A253467 A253468

Keyword

nonn

Author

R. H. Hardin, Jan 01 2015

Status

approved