A223931 Number of nX6 0..2 arrays with rows, columns and antidiagonals unimodal and diagonals nondecreasing

148, 4690, 49646, 316136, 1548633, 6621074, 26250443, 98910688, 356869229, 1233491661, 4078987936, 12893958739, 38971222534, 112766372283, 313016886779, 835552379045, 2150549167905, 5351315229801, 12907390753903, 30251757926890

Offset

1,1

Comments

Column 6 of A223933

Links

R. H. Hardin, Table of n, a(n) for n = 1..141

Formula

Empirical: a(n) = (1/35608838483312640000)*n^24 - (1/989134402314240000)*n^23 + (1/12843374100480000)*n^22 - (6449/4257578514309120000)*n^21 + (21257/304112751022080000)*n^20 - (829363/1216451004088320000)*n^19 + (40421209/896332318801920000)*n^18 - (9123221/16598746644480000)*n^17 + (633266813/17575143505920000)*n^16 - (337664083/599152619520000)*n^15 + (2727091523/144850083840000)*n^14 - (437501744297/941525544960000)*n^13 + (331492439551297/26362715258880000)*n^12 - (779880875442583/2929190584320000)*n^11 + (6466629168070943/1351934115840000)*n^10 - (1887207111269150711/26362715258880000)*n^9 + (1852948610513538961/2000741783040000)*n^8 - (82282526794806272279/8002967132160000)*n^7 + (671840992562382243287/6956827637760000)*n^6 - (3984160216854431049887/5375730447360000)*n^5 + (4404199128820894274957/985550582016000)*n^4 - (7353970133174044661/365018734080)*n^3 + (398286504848891623/6290282880)*n^2 - (651587469103938359/5354228880)*n + 102401506 for n>12

Example

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

Crossrefs

Sequence in context: A224260 A223916 A224188 * A224055 A224308 A224372

Adjacent sequences: A223928 A223929 A223930 * A223932 A223933 A223934

Keyword

nonn

Author

R. H. Hardin Mar 29 2013

Status

approved