A223807 Number of nX3 0..3 arrays with rows, columns, diagonals and antidiagonals unimodal

50, 2500, 58806, 825896, 8165133, 62305953, 388531932, 2057610878, 9513089522, 39201336756, 146317003838, 501049337826, 1590725248238, 4722687426852, 13206968194237, 35002231000213, 88376951307032, 213545507535686

Offset

1,1

Comments

Column 3 of A223811

Links

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

Formula

Empirical: a(n) = (89/169374965760)*n^18 + (838301/44460928512000)*n^17 + (131561/298896998400)*n^16 + (2899703/435891456000)*n^15 + (20728921/261534873600)*n^14 + (44295233/62270208000)*n^13 + (61053571/11496038400)*n^12 + (1555111843/50295168000)*n^11 + (157620907/1045094400)*n^10 + (3423292861/6096384000)*n^9 + (56948336183/32188907520)*n^8 + (18757539769/4790016000)*n^7 + (288950150603/37362124800)*n^6 + (2420059673699/326918592000)*n^5 + (12916777153/889574400)*n^4 + (2892057797/4540536000)*n^3 + (22972148831/1029188160)*n^2 - (1109957/29172)*n + 29

Example

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

Crossrefs

Sequence in context: A120998 A267061 A223191 * A223757 A223845 A223871

Adjacent sequences: A223804 A223805 A223806 * A223808 A223809 A223810

Keyword

nonn

Author

R. H. Hardin Mar 27 2013

Status

approved