A253751 Number of (3+1)X(n+1) 0..2 arrays with every 2X2 subblock ne-sw antidiagonal difference nondecreasing horizontally and nw+se diagonal sum nondecreasing vertically

1998, 16625, 77414, 247252, 583698, 1204422, 2363797, 4404701, 7884084, 14024725, 25106259, 45066424, 81275585, 147957366, 271721790, 502088605, 932375372, 1738806953, 3252858270, 6097945230, 11448266368, 21515673019, 40464913904

Offset

1,1

Comments

Row 3 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) -8*a(n-4) -10*a(n-5) +35*a(n-6) -47*a(n-7) +42*a(n-8) -10*a(n-9) -40*a(n-10) +68*a(n-11) -68*a(n-12) +40*a(n-13) +10*a(n-14) -42*a(n-15) +47*a(n-16) -35*a(n-17) +10*a(n-18) +8*a(n-19) -12*a(n-20) +10*a(n-21) -5*a(n-22) +a(n-23) for n>30

Example

Some solutions for n=3
..0..0..0..0....1..0..1..2....0..0..0..0....1..0..0..0....0..1..0..2
..2..1..0..2....1..0..1..1....0..0..0..1....2..0..0..0....1..0..0..1
..1..0..0..2....2..1..1..1....2..0..0..1....2..0..0..1....1..1..1..2
..2..2..2..2....1..1..0..1....2..0..1..1....2..2..1..2....2..2..0..2

Crossrefs

Sequence in context: A171467 A258106 A253744 * A031808 A167292 A230202

Adjacent sequences: A253748 A253749 A253750 * A253752 A253753 A253754

Keyword

nonn

Author

R. H. Hardin, Jan 11 2015

Status

approved