login
A278325
T(n,k)=Number of nXk 0..1 arrays with rows and columns in lexicographic nondecreasing order but with exactly two mistakes.
8
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
1,5
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
LINKS
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]
EXAMPLE
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
CROSSREFS
Column 1 is A000389(n+1).
Sequence in context: A350212 A256311 A022695 * A364527 A226780 A270880
KEYWORD
nonn,tabl
AUTHOR
R. H. Hardin, Nov 18 2016
STATUS
approved