A266547 T(n,k)=Number of nXk binary arrays with rows and columns lexicographically nondecreasing and row and column sums nonincreasing.

2, 2, 2, 2, 3, 2, 2, 3, 3, 2, 2, 4, 5, 4, 2, 2, 4, 6, 6, 4, 2, 2, 5, 8, 12, 8, 5, 2, 2, 5, 11, 16, 16, 11, 5, 2, 2, 6, 13, 27, 36, 27, 13, 6, 2, 2, 6, 16, 36, 58, 58, 36, 16, 6, 2, 2, 7, 20, 57, 110, 176, 110, 57, 20, 7, 2, 2, 7, 23, 76, 196, 366, 366, 196, 76, 23, 7, 2, 2, 8, 27, 114, 363

Offset: 1

Author

R. H. Hardin, Dec 31 2015

Keywords

• nonn
• tabl

Comments

Table starts

.2.2..2...2...2....2......2.......2........2........2........2........2.......2

.2.3..3...4...4....5......5.......6........6........7........7........8.......8

.2.3..5...6...8...11.....13......16.......20.......23.......27.......32......36

.2.4..6..12..16...27.....36......57.......76......114......149......213.....276

.2.4..8..16..36...58....110.....196......363......695.....1157.....2023....3446

.2.5.11..27..58..176....366....1062.....2571.....7345....17540....47970..109375

.2.5.13..36.110..366...1688....5312....24921...101495...417118..1673507.6081357

.2.6.16..57.196.1062...5312...48167...264355..2251914.13562215.97760446

.2.6.20..76.363.2571..24921..264355..4283651.40874990

.2.7.23.114.695.7345.101495.2251914.40874990

Examples

			Some solutions for n=6 k=4
..0..0..1..1....0..0..1..1....0..0..0..1....0..0..1..1....0..0..1..1
..0..1..0..1....0..1..0..0....0..0..1..0....0..0..1..1....0..0..1..1
..1..0..1..0....1..0..0..0....0..1..0..0....0..0..1..1....1..1..0..0
..1..1..0..0....1..0..0..0....0..1..0..0....1..1..0..0....1..1..0..0
..1..1..0..0....1..0..0..0....1..0..0..0....1..1..0..0....1..1..0..0
..1..1..0..0....1..0..0..0....1..0..0..0....1..1..0..0....1..1..0..0
		

Links

• R. H. Hardin, Table of n, a(n) for n = 1..179

Crossrefs

Column 2 is A004526(n+4).

Formula

Empirical for column k:

k=1: a(n) = a(n-1)

k=2: a(n) = a(n-1) +a(n-2) -a(n-3)

k=3: a(n) = 2*a(n-1) -a(n-2) +a(n-3) -2*a(n-4) +a(n-5)

k=4: [order 17]