A266431 - OEIS

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

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OFFSET

1,1

COMMENTS

Row 5 of A266428.

LINKS

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

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

EXAMPLE

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

CROSSREFS

Cf. A266428.

Sequence in context: A231058 A317178 A218893 * A063090 A184185 A216317

Adjacent sequences: A266428 A266429 A266430 * A266432 A266433 A266434

KEYWORD

nonn

AUTHOR

R. H. Hardin, Dec 29 2015

STATUS

approved