A224310 T(n,k)=Number of nXk 0..2 arrays with diagonals and rows unimodal and antidiagonals nondecreasing.
3, 9, 9, 22, 54, 27, 46, 218, 324, 81, 86, 698, 1586, 1944, 243, 148, 1915, 5996, 11361, 11664, 729, 239, 4690, 20214, 45453, 82700, 69984, 2187, 367, 10511, 61953, 164514, 345875, 615481, 419904, 6561, 541, 21919, 174378, 562760, 1258372, 2717759
Offset: 1
Examples
Some solutions for n=3 k=4 ..0..0..1..0....0..0..0..1....0..0..0..1....0..2..1..0....0..0..2..0 ..1..2..1..0....0..1..1..0....0..0..1..0....2..1..1..0....2..2..2..0 ..2..1..1..1....1..2..2..2....2..2..0..0....1..1..2..0....2..2..1..0
Links
- R. H. Hardin, Table of n, a(n) for n = 1..337
Formula
Empirical for column k:
k=1: a(n) = 3*a(n-1)
k=2: a(n) = 6*a(n-1)
k=3: [order 17]
k=4: [order 30] for n>35
k=5: [order 61] for n>69
k=6: [order 88] for n>98
Empirical: rows n=1..7 are polynomials of degree 4*n for k>0,0,3,6,9,12,15
Comments