A253466 Number of (n+1) X (5+1) 0..2 arrays with every 2 X 2 subblock diagonal maximum minus antidiagonal minimum unequal to its neighbors horizontally, vertically, diagonally and antidiagonally.

162016, 8536, 5000, 7496, 8000, 12680, 20000, 33416, 68000, 116360, 260000, 448136, 1028000, 1775240, 4100000, 7083656, 16388000, 28317320, 65540000, 113251976, 262148000, 452990600, 1048580000, 1811945096, 4194308000, 7247763080

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*(20252 + 1067*x - 100635*x^2 - 4398*x^3 + 78883*x^4 + 1168*x^5) / ((1 - x)*(1 + x)*(1 - 2*x)*(1 + 2*x)). - Colin Barker, Dec 14 2018

Example

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

Crossrefs

Column 5 of A253468.

Sequence in context: A114669 A204306 A120409 * A225811 A244348 A083633

Adjacent sequences: A253463 A253464 A253465 * A253467 A253468 A253469

Keyword

nonn

Author

R. H. Hardin, Jan 01 2015

Status

approved