A250694 Number of (3+1)X(n+1) 0..3 arrays with nondecreasing x(i,j)-x(i,j-1) in the i direction and nondecreasing absolute value of x(i,j)-x(i-1,j) in the j direction

2512, 15246, 74631, 324648, 1315446, 5098590, 19218493, 71223396, 261469392, 955896790, 3493273891, 12795574192, 47067986826, 174102348110, 648137931065, 2429513706796, 9171278516740, 34862473392934, 133406490904351

Offset

1,1

Comments

Row 3 of A250691

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
..2..1..3..1....3..0..1..0....2..3..1..0....1..1..1..0....0..1..1..2
..1..0..2..0....2..1..2..1....2..3..2..2....1..1..2..2....0..1..1..2
..2..1..3..2....2..2..3..3....0..1..0..0....1..1..2..2....0..1..1..2
..1..0..2..3....0..0..1..1....0..1..2..3....2..2..3..3....0..1..1..3

Crossrefs

Sequence in context: A031621 A212400 A215197 * A250679 A145534 A166931

Adjacent sequences: A250691 A250692 A250693 * A250695 A250696 A250697

Keyword

nonn

Author

R. H. Hardin, Nov 26 2014

Status

approved