A203722 Number of (n+1)X3 0..2 arrays with column and row pair sums b(i,j)=a(i,j)+a(i,j-1) and c(i,j)=a(i,j)+a(i-1,j) nondecreasing in column and row directions, respectively

113, 480, 1632, 4737, 12470, 30335, 69612, 152260, 320546, 653622, 1298042, 2520746, 4803363, 9005619, 16650695, 30417076, 54987344, 98502681, 175052609, 308918598, 541794370, 945035051, 1640400129, 2835103075, 4880936409

Offset

1,1

Comments

Column 2 of A203728

Links

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

Formula

Empirical: a(n) = 6*a(n-1) -10*a(n-2) -8*a(n-3) +40*a(n-4) -22*a(n-5) -47*a(n-6) +56*a(n-7) +15*a(n-8) -46*a(n-9) +8*a(n-10) +16*a(n-11) -6*a(n-12) -2*a(n-13) +a(n-14) for n>15

Example

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

Crossrefs

Sequence in context: A342816 A353957 A142850 * A118506 A341230 A109563

Adjacent sequences: A203719 A203720 A203721 * A203723 A203724 A203725

Keyword

nonn

Author

R. H. Hardin Jan 05 2012

Status

approved