A278627 T(n,k)=Number of nXk 0..2 arrays with rows in nondecreasing lexicographic order and columns in nonincreasing lexicographic order, but with exactly one mistake.
0, 3, 3, 16, 46, 16, 51, 357, 357, 51, 126, 1952, 4754, 1952, 126, 266, 8518, 49503, 49503, 8518, 266, 504, 31605, 439446, 1069536, 439446, 31605, 504, 882, 103546, 3438414, 21121532, 21121532, 3438414, 103546, 882, 1452, 307087, 24103803
Offset: 1
Examples
Some solutions for n=3 k=4 ..1..1..0..0. .2..2..1..1. .1..1..1..0. .2..1..0..0. .1..2..1..1 ..1..0..1..0. .1..1..2..2. .2..2..2..1. .2..1..1..0. .1..2..2..0 ..2..1..1..2. .2..0..2..2. .2..1..0..1. .0..0..2..2. .2..1..0..1
Links
- R. H. Hardin, Table of n, a(n) for n = 1..127
Crossrefs
Column 1 is A000574(n+1).
Formula
Empirical for column k:
k=1: a(n) = (1/120)*n^5 + (1/8)*n^4 + (5/24)*n^3 - (1/8)*n^2 - (13/60)*n
k=2: [polynomial of degree 15]
k=3: [polynomial of degree 43]
k=4: [polynomial of degree 125]
Comments