A224028 Number of 6Xn 0..3 arrays with rows nondecreasing and antidiagonals unimodal

4096, 1000000, 30756756, 403836633, 3491241557, 23151623729, 126168072638, 589287463547, 2427724545612, 9007001464858, 30566042176352, 96033091778636, 282028543897612, 780257746938799, 2046679053764299, 5117642427934938

Offset

1,1

Comments

Row 6 of A224024

Links

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

Formula

Empirical: a(n) = (42587101/1600593426432000)*n^18 + (23341517/16167610368000)*n^17 + (15783371/356638464000)*n^16 + (31606091/33965568000)*n^15 + (17663092277/1207084032000)*n^14 + (133630090943/747242496000)*n^13 + (3090381263819/1810626048000)*n^12 + (861240248921/67060224000)*n^11 + (16435251844841/219469824000)*n^10 + (3455775661663/10450944000)*n^9 + (654929669980007/603542016000)*n^8 + (1738593710779/653184000)*n^7 + (82071435647381/16717428000)*n^6 + (429177771626699/59439744000)*n^5 - (15320544442081/40864824000)*n^4 - (2761354550633/92664000)*n^3 - (36294722496521/593762400)*n^2 + (776634903133/6126120)*n + 95040 for n>4

Example

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

Crossrefs

Sequence in context: A236218 A016962 A224395 * A269206 A183816 A224285

Adjacent sequences: A224025 A224026 A224027 * A224029 A224030 A224031

Keyword

nonn

Author

R. H. Hardin Mar 30 2013

Status

approved