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A266471 Number of 4Xn binary arrays with rows and columns lexicographically nondecreasing and column sums nonincreasing. 1
5, 12, 29, 66, 137, 261, 463, 775, 1237, 1898, 2817, 4064, 5721, 7883, 10659, 14173, 18565, 23992, 30629, 38670, 48329, 59841, 73463, 89475, 108181, 129910, 155017, 183884, 216921, 254567, 297291, 345593, 400005, 461092, 529453, 605722, 690569 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

Row 4 of A266470.

LINKS

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

FORMULA

Empirical: a(n) = (1/120)*n^5 + (1/24)*n^4 + (17/24)*n^3 - (25/24)*n^2 + (257/60)*n + 1

EXAMPLE

Some solutions for n=4

..0..0..0..0....0..0..0..0....0..1..1..1....0..0..0..0....0..0..1..1

..0..0..0..0....0..0..0..0....1..0..0..0....0..0..1..1....0..1..0..0

..1..1..1..1....0..0..0..0....1..0..1..1....1..1..0..0....1..0..0..0

..1..1..1..1....1..1..1..1....1..1..0..0....1..1..1..1....1..1..1..1

CROSSREFS

Cf. A266470.

Sequence in context: A196410 A000465 A283506 * A069306 A277088 A009412

Adjacent sequences:  A266468 A266469 A266470 * A266472 A266473 A266474

KEYWORD

nonn

AUTHOR

R. H. Hardin, Dec 29 2015

STATUS

approved

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Last modified October 20 11:53 EDT 2018. Contains 316379 sequences. (Running on oeis4.)