A224193 Number of 6Xn 0..2 arrays with rows unimodal and columns nondecreasing.

28, 784, 13524, 163746, 1519738, 11444292, 72710554, 400958714, 1960596602, 8643660124, 34817290272, 129528551708, 449030731802, 1461369918218, 4493166765659, 13121663640985, 36566337458326, 97628603745396

Offset: 1

Author

R. H. Hardin Apr 01 2013

Keywords

• nonn

Comments

Row 6 of A224190

Examples

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

Links

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

Formula

Empirical: a(n) = (1/35608838483312640000)*n^24 + (1/228261785149440000)*n^23 + (2993/8515157028618240000)*n^22 + (1189/64508765368320000)*n^21 + (112787/162193467211776000)*n^20 + (4033303/202741834014720000)*n^19 + (100023181/224083079700480000)*n^18 + (75069509/9336794987520000)*n^17 + (1246517053/10545086103552000)*n^16 + (6306246257/4393785876480000)*n^15 + (18213412351/1255367393280000)*n^14 + (38516770459/313841848320000)*n^13 + (9185104716379/10545086103552000)*n^12 + (1753572682469/337983528960000)*n^11 + (42653443424521/1647669703680000)*n^10 + (118327836601829/1098446469120000)*n^9 + (1768182454793/4763670912000)*n^8 + (698418986666497/666913927680000)*n^7 + (26428459959973901/11087444047680000)*n^6 + (31671555902461499/7391629365120000)*n^5 + (14625059352544909/2463876455040000)*n^4 + (438413487383/71292721500)*n^3 + (10755031442327/2248776129600)*n^2 + (2550558151/1338557220)*n + 1