A229776 Number of 4X4 0..n arrays with rows in lexicographically nondecreasing order and columns in nonincreasing order.

70, 12958, 1058494, 35452250, 637396928, 7379634620, 61734072288, 402537583863, 2155573868470, 9841145888530, 39380724254950, 141067066333648, 459822149867432, 1381730749348760, 3867950992777232, 10173948824534685

Offset: 1

Author

R. H. Hardin, Sep 29 2013

Keywords

• nonn

Comments

Row 4 of A229774

Examples

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

Links

• R. H. Hardin, Table of n, a(n) for n = 1..42

Formula

Empirical: a(n) = (1/5040)*n^16 + (17/5040)*n^15 + (89/3360)*n^14 + (143/1120)*n^13 + (307/720)*n^12 + (307/288)*n^11 + (64247/30240)*n^10 + (53933/15120)*n^9 + (10645/2016)*n^8 + (71609/10080)*n^7 + (44/5)*n^6 + (14447/1440)*n^5 + (8975/864)*n^4 + (20359/2160)*n^3 + (3505/504)*n^2 + (1543/420)*n + 1