A185435 T(n,k)=Number of (n+2)X(k+2) 0..7 arrays with each 3X3 subblock having rows and columns in lexicographically nondecreasing order.
6842284, 284037544, 284037544, 8653394212, 21536560306, 8653394212, 212298419684, 1090205284029, 1090205284029, 212298419684, 4370405405266, 41910604337378, 84722449466168, 41910604337378, 4370405405266
Offset: 1
Examples
Some solutions for 5X4 ..0..0..0..0....0..0..0..0....0..0..0..0....0..0..0..0....0..0..0..0 ..0..0..0..0....0..0..0..0....0..0..0..0....0..0..0..0....0..0..0..0 ..0..0..0..0....0..0..0..4....0..0..0..0....0..0..0..0....0..0..0..4 ..0..1..1..2....0..0..2..3....0..1..4..5....0..0..5..6....0..0..6..7 ..0..3..7..3....0..7..0..5....0..2..1..6....2..2..6..4....0..4..3..0
Links
- R. H. Hardin, Table of n, a(n) for n = 1..83
- R. H. Hardin, Polynomials for columns 1-3
Formula
Empirical: T(n,k) is a polynomial of degree 7k+112, for fixed k
Let T(n,k,z) be the number of (n+2)X(k+2) 0..z arrays with each 3X3 subblock having rows and columns in lexicographically nondecreasing order
Then empirically T(n,k,z) is a polynomial of degree z*k + z*(z+1)*(z+5)/6 in n, for fixed k.
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