A253492 Number of (n+1) X (5+1) 0..2 arrays with every 2 X 2 subblock diagonal minus antidiagonal sum nondecreasing horizontally, vertically and ne-to-sw antidiagonally.

8501, 9679, 11937, 18526, 32652, 63550, 133284, 296566, 694572, 1704910, 4368564, 11624806, 31924092, 89883070, 257882244, 750124246, 2203339212, 6515962030, 19359786324, 57703170886, 172357147932, 515566725790, 1543690752804

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>6.

Empirical: a(n) = 49*3^(n-1) + 1435*2^(n-1) + 5723 for n>3.

Conjectures from Colin Barker, Dec 15 2018: (Start)

G.f.: x*(8501 - 41327*x + 47374*x^2 + 2367*x^3 - 5271*x^4 - 198*x^5) / ((1 - x)*(1 - 2*x)*(1 - 3*x)).

a(n) = (34338 + 4305*2^n + 98*3^n) / 6 for n>3.

(End)

Example

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

Crossrefs

Column 5 of A253495.

Sequence in context: A031590 A322160 A253499 * A253453 A348605 A260988

Adjacent sequences: A253489 A253490 A253491 * A253493 A253494 A253495

Keyword

nonn

Author

R. H. Hardin, Jan 02 2015

Status

approved