A266431 Number of 5Xn binary arrays with rows and columns lexicographically nondecreasing and column sums nondecreasing.

6, 34, 212, 1391, 8764, 49894, 251381, 1122721, 4490732, 16284683, 54165714, 166968275, 481237398, 1306708520, 3364174219, 8257222586, 19412425379, 43890267973, 95767324137, 202278568268, 414691101885, 827108931171

Offset: 1

Author

R. H. Hardin, Dec 29 2015

Keywords

• nonn

Comments

Row 5 of A266428.

Examples

			Some solutions for n=4
..0..0..1..1....0..1..1..1....0..0..1..1....0..0..0..1....0..0..0..1
..0..0..1..1....0..1..1..1....0..1..0..1....0..0..1..1....0..0..1..0
..0..0..1..1....0..1..1..1....1..0..1..0....0..1..1..1....0..0..1..1
..0..1..0..0....1..1..1..1....1..1..0..0....1..0..1..1....0..1..1..1
..1..1..0..0....1..1..1..1....1..1..1..1....1..1..1..0....1..1..0..1
		

Links

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

Crossrefs

Cf. A266428.

Formula

Empirical: a(n) = (1/7602818775552000)*n^19 + (1/47076277248000)*n^18 + (389/266765571072000)*n^17 + (47/815173632000)*n^16 + (11629/7846046208000)*n^15 + (413249/15692092416000)*n^14 + (7941701/23538138624000)*n^13 + (23266079/7242504192000)*n^12 + (14091433/603542016000)*n^11 + (267047/1959552000)*n^10 + (794703337/1207084032000)*n^9 + (14650018639/4828336128000)*n^8 + (267287875667/23538138624000)*n^7 + (102484112767/2139830784000)*n^6 + (39001810891/326918592000)*n^5 + (73310538271/186810624000)*n^4 + (87546462023/102918816000)*n^3 + (113077535/72648576)*n^2 + (469781209/232792560)*n + 1