A253750 Number of (2+1)X(n+1) 0..2 arrays with every 2X2 subblock ne-sw antidiagonal difference nondecreasing horizontally and nw+se diagonal sum nondecreasing vertically

450, 2723, 10182, 29737, 70590, 148134, 298760, 587522, 1126853, 2134789, 4034824, 7609993, 14320586, 26934197, 50677637, 95365268, 179465371, 337787639, 635898370, 1197229227, 2254216671, 4244626838, 7992870420, 15051425511

Offset

1,1

Comments

Row 2 of A253749

Links

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

Formula

Empirical: a(n) = 5*a(n-1) -10*a(n-2) +12*a(n-3) -9*a(n-4) -5*a(n-5) +25*a(n-6) -35*a(n-7) +33*a(n-8) -15*a(n-9) -15*a(n-10) +33*a(n-11) -35*a(n-12) +25*a(n-13) -5*a(n-14) -9*a(n-15) +12*a(n-16) -10*a(n-17) +5*a(n-18) -a(n-19) for n>25

Example

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

Crossrefs

Sequence in context: A079659 A304511 A202197 * A253743 A253369 A253376

Adjacent sequences: A253747 A253748 A253749 * A253751 A253752 A253753

Keyword

nonn

Author

R. H. Hardin, Jan 11 2015

Status

approved