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A180983 T(n,k)=number of nXk binary matrices with floor((n*k)/2) 1's and rows in lexicographically nondecreasing order and columns in strictly increasing order 2
1, 1, 1, 0, 2, 1, 0, 1, 4, 1, 0, 1, 6, 6, 1, 0, 0, 10, 20, 9, 1, 0, 0, 9, 71, 49, 12, 1, 0, 0, 6, 200, 368, 109, 16, 1, 0, 0, 3, 450, 2403, 1502, 222, 20, 1, 0, 0, 1, 780, 13059, 19929, 5208, 412, 25, 1, 0, 0, 0, 1042, 60488, 238535, 135984, 15983, 712, 30, 1, 0, 0, 0, 1084 (list; table; graph; refs; listen; history; text; internal format)
OFFSET

1,5

COMMENTS

Table starts

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

.1..2....1......1........0..........0............0..............0

.1..4....6.....10........9..........6............3..............1

.1..6...20.....71......200........450..........780...........1042

.1..9...49....368.....2403......13059........60488.........221320

.1.12..109...1502....19929.....238535......2448773.......21398553

.1.16..222...5208...135984....3267300.....73506103.....1350956543

.1.20..412..15983...755144...36506260...1632383886....64732546521

.1.25..712..44485..3831820..348892547..32320317217..2541063599189

.1.30.1177.114320.16788240.2938265005.519815199311.85375670050862

LINKS

R. H. Hardin, Table of n, a(n) for n=1..199

EXAMPLE

All solutions for 3X4

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

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

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

...

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

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

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

CROSSREFS

Sequence in context: A109970 A116088 A136501 * A127709 A128307 A034369

Adjacent sequences:  A180980 A180981 A180982 * A180984 A180985 A180986

KEYWORD

nonn,tabl

AUTHOR

R. H. Hardin Sep 30 2010

STATUS

approved

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Last modified December 12 20:12 EST 2019. Contains 329961 sequences. (Running on oeis4.)