A278325 T(n,k)=Number of nXk 0..1 arrays with rows and columns in lexicographic nondecreasing order but with exactly two mistakes.

0, 0, 0, 0, 3, 0, 1, 20, 20, 1, 6, 94, 236, 94, 6, 21, 395, 1678, 1678, 395, 21, 56, 1492, 9714, 19854, 9714, 1492, 56, 126, 4991, 51229, 186987, 186987, 51229, 4991, 126, 252, 14848, 251892, 1548002, 3058990, 1548002, 251892, 14848, 252, 462, 39832, 1144205

Offset: 1

Author

R. H. Hardin, Nov 18 2016

Keywords

• nonn
• tabl

Comments

Table starts

...0.....0........0..........1............6..............21................56

...0.....3.......20.........94..........395............1492..............4991

...0....20......236.......1678.........9714...........51229............251892

...1....94.....1678......19854.......186987.........1548002..........11947350

...6...395.....9714.....186987......3058990........43798840.........570738085

..21..1492....51229....1548002.....43798840......1133034160.......26606146271

..56..4991...251892...11947350....570738085.....26606146271.....1159826452573

.126.14848..1144205...87562135...7010453565....577253086055....46588303100299

.252.39832..4762445..605431820..82490704797..11856994168275..1741053359883624

.462.97835.18164685.3905165468.927749763030.234252250004719.61687083048618477

Examples

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

Links

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

Crossrefs

Column 1 is A000389(n+1).

Formula

Empirical for column k:

k=1: a(n) = (1/120)*n^5 - (1/24)*n^4 + (1/24)*n^3 + (1/24)*n^2 - (1/20)*n

k=2: [polynomial of degree 11]

k=3: [polynomial of degree 23]

k=4: [polynomial of degree 47]

k=5: [polynomial of degree 95]