A250850 Number of (n+1) X (5+1) 0..3 arrays with nondecreasing x(i,j)-x(i,j-1) in the i direction and nondecreasing min(x(i,j),x(i-1,j)) in the j direction.

7056, 49599, 290646, 1499679, 7134786, 32201019, 140301126, 596722599, 2495502666, 10311967539, 42245985006, 171994777119, 697044608946, 2815440919659, 11343683099286, 45620754601239, 183221612905626

Offset

1,1

Links

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

Formula

Empirical: a(n) = 10*a(n-1) - 35*a(n-2) + 50*a(n-3) - 24*a(n-4); a(n) = (129528*4^n - 206190*3^n + 96660*2^n - 8190)/12.

Empirical g.f.: 9*x*(784 - 2329*x + 4624*x^2 - 2624*x^3) / ((1 - x)*(1 - 2*x)*(1 - 3*x)*(1 - 4*x)). - Colin Barker, Nov 21 2018

Example

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

Crossrefs

Column 5 of A250853.

Sequence in context: A206050 A116332 A234545 * A071131 A238520 A230975

Adjacent sequences: A250847 A250848 A250849 * A250851 A250852 A250853

Keyword

nonn

Author

R. H. Hardin, Nov 28 2014

Status

approved