A223770 T(n,k)=Number of nXk 0..1 arrays with rows, columns and antidiagonals unimodal and diagonals nondecreasing.
2, 4, 4, 7, 12, 7, 11, 28, 28, 11, 16, 56, 71, 56, 16, 22, 101, 155, 155, 101, 22, 29, 169, 317, 361, 317, 169, 29, 37, 267, 607, 782, 782, 607, 267, 37, 46, 403, 1097, 1601, 1748, 1601, 1097, 403, 46, 56, 586, 1887, 3141, 3699, 3699, 3141, 1887, 586, 56, 67, 826
Offset: 1
Examples
Some solutions for n=3 k=4 ..0..0..0..1....0..0..0..0....1..1..0..0....0..0..1..0....0..0..1..0 ..0..0..0..1....1..0..0..0....1..1..1..0....1..1..1..1....0..1..1..1 ..0..0..0..1....1..1..1..1....1..1..1..1....0..1..1..1....0..1..1..1
Links
- R. H. Hardin, Table of n, a(n) for n = 1..363
Crossrefs
Column 1 is A000124
Formula
Empirical: columns 1..7 are polynomials of degree 2*k for n>0,0,2,4,6,8,10
Comments