A250538 Number of (n+1)X(2+1) 0..3 arrays with nondecreasing x(i,j)-x(i,j-1) in the i direction and nondecreasing x(i,j)-x(i-1,j) in the j direction

1080, 10704, 79366, 491650, 2701872, 13657024, 64993652, 295871112, 1302924116, 5595784456, 23580939154, 97951328382, 402468021792, 1640200686104, 6643744925312, 26790344223060, 107678819237476, 431796331093984

Offset

1,1

Comments

Column 2 of A250544

Links

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

Formula

Empirical: a(n) = 30*a(n-1) -415*a(n-2) +3514*a(n-3) -20386*a(n-4) +85924*a(n-5) -272198*a(n-6) +661180*a(n-7) -1244717*a(n-8) +1822478*a(n-9) -2068955*a(n-10) +1802474*a(n-11) -1181760*a(n-12) +563888*a(n-13) -184752*a(n-14) +37152*a(n-15) -3456*a(n-16)

Example

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

Crossrefs

Sequence in context: A214621 A179688 A159210 * A281259 A251795 A092135

Adjacent sequences: A250535 A250536 A250537 * A250539 A250540 A250541

Keyword

nonn

Author

R. H. Hardin, Nov 24 2014

Status

approved