A224169 Number of n X 4 0..3 arrays with rows, diagonals and antidiagonals unimodal and columns nondecreasing.

130, 3526, 38561, 272130, 1460836, 6425876, 24197608, 80350989, 240416852, 658890738, 1675303647, 3992383968, 8991162356, 19265941324, 39500748718, 77861024489, 148143119762, 273013479180, 488783426991, 852309147046, 1450785202572, 2415419887660, 3940248617356

Offset: 1

Author

R. H. Hardin, Mar 31 2013

Keywords

• nonn

Examples

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

Links

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

Crossrefs

Column 4 of A224173.

Formula

Empirical: a(n) = (3551/47900160)*n^12 + (17561/13305600)*n^11 + (376693/21772800)*n^10 + (106499/725760)*n^9 + (229093/290304)*n^8 + (4775993/1209600)*n^7 + (239805679/21772800)*n^6 + (2313469/80640)*n^5 + (85217281/1088640)*n^4 - (37150333/907200)*n^3 - (7297121/207900)*n^2 + (474241/1386)*n - 383 for n>3.

Extensions

Name corrected by Andrew Howroyd, Mar 18 2025