A253453 Number of (n+1) X (5+1) 0..2 arrays with every 2 X 2 subblock diagonal minus antidiagonal sum nondecreasing horizontally and vertically.

8501, 15220, 19254, 26831, 44242, 83003, 170184, 373130, 864720, 2104994, 5356824, 14174330, 38750880, 108728594, 311157864, 903437930, 2650262640, 7830705794, 23251973304, 69275651930, 206866440000, 618678308594, 1852192923144

Offset

1,1

Links

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

Formula

Empirical: a(n) = 6*a(n-1) - 11*a(n-2) + 6*a(n-3) for n>9.

Empirical: a(n) = 529*3^(n-3) + 1832*2^(n-1) + 10087 for n>6.

Empirical g.f.: x*(8501 - 35786*x + 21445*x^2 + 27721*x^3 + 3730*x^4 - 2832*x^5 - 2158*x^6 - 393*x^7 - 54*x^8) / ((1 - x)*(1 - 2*x)*(1 - 3*x)). - Colin Barker, Dec 13 2018

Example

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

Crossrefs

Column 5 of A253456.

Sequence in context: A322160 A253499 A253492 * A348605 A260988 A188214

Adjacent sequences: A253450 A253451 A253452 * A253454 A253455 A253456

Keyword

nonn

Author

R. H. Hardin, Jan 01 2015

Status

approved