A223789 T(n,k)=Number of nXk 0..2 arrays with rows, diagonals and antidiagonals unimodal.
3, 9, 9, 22, 81, 27, 46, 484, 729, 81, 86, 2116, 8635, 6561, 243, 148, 7396, 62365, 151580, 59049, 729, 239, 21904, 334230, 1560013, 2703137, 531441, 2187, 367, 57121, 1455816, 11012718, 39387861, 48302789, 4782969, 6561, 541, 134689, 5425943
Offset: 1
Examples
Some solutions for n=3 k=4 ..2..2..2..1....1..2..0..0....1..1..2..2....1..2..1..1....0..0..0..0 ..0..2..2..1....0..0..1..0....0..2..2..1....1..1..2..0....0..1..2..0 ..2..1..0..0....0..1..0..0....0..2..0..0....2..2..2..2....0..0..1..0
Links
- R. H. Hardin, Table of n, a(n) for n = 1..126
Formula
Empirical for column k:
k=1: a(n) = 3*a(n-1)
k=2: a(n) = 9*a(n-1)
k=3: [order 15]
k=4: [order 80]
Empirical: rows n=1..5 are polynomials of order 4*n for k>0,0,1,8,15
Comments