A253469 Number of (n+1) X (7+1) 0..2 arrays with every 2 X 2 subblock diagonal maximum minus antidiagonal minimum unequal to its neighbors horizontally, vertically, diagonally and antidiagonally.

7227096, 44464, 17000, 15680, 20000, 20864, 32000, 41600, 80000, 124544, 272000, 456320, 1040000, 1783424, 4112000, 7091840, 16400000, 28325504, 65552000, 113260160, 262160000, 452998784, 1048592000, 1811953280, 4194320000

Offset

1,1

Links

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

Formula

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

Empirical g.f.: 8*x*(903387 + 5558*x - 4514810*x^2 - 25830*x^3 + 3605423*x^4 + 15040*x^5) / ((1 - x)*(1 + x)*(1 - 2*x)*(1 + 2*x)). - Colin Barker, Dec 15 2018

Example

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

Crossrefs

Column 7 of A253468.

Sequence in context: A286010 A184214 A181680 * A325606 A157378 A251356

Adjacent sequences: A253466 A253467 A253468 * A253470 A253471 A253472

Keyword

nonn

Author

R. H. Hardin, Jan 01 2015

Status

approved