A223966 Number of 6Xn 0..3 arrays with antidiagonals unimodal and rows and diagonals nondecreasing.

4096, 403104, 5777663, 37844037, 163752797, 556027700, 1629022329, 4351046624, 10953882109, 26519610433, 62472567689, 144124515790, 326646013571, 728132468716, 1596498777021, 3441674914130, 7290815852670, 15169818503342

Offset: 1

Author

R. H. Hardin Mar 29 2013

Keywords

• nonn

Comments

Row 6 of A223961

Examples

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

Links

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

Formula

Empirical: a(n) = (1/73156608000)*n^18 + (1/2709504000)*n^17 + (3319/268240896000)*n^16 + (247579/871782912000)*n^15 + (1111849/193729536000)*n^14 + (3684553/35582976000)*n^13 + (658841977/402361344000)*n^12 + (521443357/22353408000)*n^11 + (7665391471/24385536000)*n^10 + (90826901857/24385536000)*n^9 + (333381059779/8128512000)*n^8 + (85061672873/217728000)*n^7 + (319642737999043/100590336000)*n^6 + (118989237432757/5588352000)*n^5 + (107614272658699/1862784000)*n^4 + (891088311042211/9081072000)*n^3 - (51719689062621/11211200)*n^2 + (1774047167507/360360)*n + 34898064 for n>11