This site is supported by donations to The OEIS Foundation.

 Hints (Greetings from The On-Line Encyclopedia of Integer Sequences!)
 A180977 T(n,k)=number of nXk binary matrices with floor((n*k)/2) 1's and rows and columns in lexicographically strictly increasing order 2
 1, 1, 1, 0, 1, 0, 0, 1, 1, 0, 0, 1, 5, 1, 0, 0, 0, 8, 8, 0, 0, 0, 0, 9, 50, 9, 0, 0, 0, 0, 6, 181, 181, 6, 0, 0, 0, 0, 3, 438, 1823, 438, 3, 0, 0, 0, 0, 1, 775, 11700, 11700, 775, 1, 0, 0, 0, 0, 0, 1039, 58090, 189359, 58090, 1039, 0, 0, 0, 0, 0, 0, 1084, 218120, 2218249, 2218249 (list; table; graph; refs; listen; history; text; internal format)
 OFFSET 1,13 COMMENTS Table starts .1.1.0....0.......0..........0............0..............0.................0 .1.1.1....1.......0..........0............0..............0.................0 .0.1.5....8.......9..........6............3..............1.................0 .0.1.8...50.....181........438..........775...........1039..............1084 .0.0.9..181....1823......11700........58090.........218120............707425 .0.0.6..438...11700.....189359......2218249.......20523612.........157471741 .0.0.3..775...58090....2218249.....61746973.....1247701323.......22218184979 .0.0.1.1039..218120...20523612...1247701323....57086318681.....2123810796163 .0.0.0.1084..707425..157471741..22218184979..2123810796163...174484293356777 .0.0.0..887.1835737.1032413434.315303186865.67142312629555.11201887329999615 LINKS R. H. Hardin, Table of n, a(n) for n=1..220 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..1..0..1....0..1..0..1 ..0..1..1..1....1..0..1..1....1..0..1..0....0..1..1..0....1..0..1..0 ... ..0..0..1..1....0..0..1..1....0..0..1..1 ..0..1..0..1....0..1..0..0....0..1..0..1 ..1..0..0..1....1..1..0..1....1..1..0..0 CROSSREFS Sequence in context: A249737 A129205 A098173 * A269129 A058177 A204619 Adjacent sequences:  A180974 A180975 A180976 * A180978 A180979 A180980 KEYWORD nonn,tabl AUTHOR R. H. Hardin Sep 30 2010 STATUS approved

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recent | More pages
The OEIS Community | Maintained by The OEIS Foundation Inc.

Last modified November 15 15:59 EST 2018. Contains 317239 sequences. (Running on oeis4.)