A224158 T(n,k)=Number of nXk 0..1 arrays with diagonals and rows unimodal and antidiagonals nondecreasing.
2, 4, 4, 7, 12, 8, 11, 28, 36, 16, 16, 56, 89, 108, 32, 22, 101, 187, 281, 324, 64, 29, 169, 373, 574, 900, 972, 128, 37, 267, 702, 1156, 1783, 2935, 2916, 256, 46, 403, 1252, 2271, 3469, 5657, 9681, 8748, 512, 56, 586, 2130, 4339, 6786, 10562, 18408, 32020, 26244
Offset: 1
Examples
Some solutions for n=3 k=4 ..0..0..0..0....1..1..0..0....0..0..1..0....0..1..1..0....0..0..1..0 ..0..0..0..0....1..0..0..0....1..1..0..0....1..1..1..1....1..1..1..0 ..0..0..1..0....0..0..0..0....1..1..1..0....1..1..1..1....1..1..1..1
Links
- R. H. Hardin, Table of n, a(n) for n = 1..797
Formula
Empirical: columns k=1..7 have recurrences of order 1,1,9,13,20,24,33 for n>0,0,0,14,22,27,37
Empirical: rows n=1..7 are polynomials of degree 2*n for k>0,0,2,4,6,8,10
Comments