A224391 T(n,k)=Number of nXk 0..3 arrays with diagonals and antidiagonals unimodal and rows nondecreasing.
4, 10, 16, 20, 100, 64, 35, 400, 1000, 256, 56, 1225, 6094, 10000, 1024, 84, 3136, 27790, 86701, 100000, 4096, 120, 7056, 102232, 497958, 1268572, 1000000, 16384, 165, 14400, 319769, 2332222, 8573507, 18794636, 10000000, 65536, 220, 27225, 881519
Offset: 1
Examples
Some solutions for n=3 k=4 ..0..1..1..1....0..1..1..3....1..2..3..3....2..2..3..3....0..0..0..1 ..2..2..2..2....0..1..3..3....0..2..2..2....0..3..3..3....0..2..2..3 ..1..3..3..3....0..2..3..3....1..1..1..1....0..0..1..2....3..3..3..3
Links
- R. H. Hardin, Table of n, a(n) for n = 1..198
Formula
Empirical for column k:
k=1: a(n) = 4*a(n-1)
k=2: a(n) = 10*a(n-1)
k=3: [order 15]
k=4: [order 47]
Empirical: rows n=1..6 are polynomials of degree 3*n for k>0,0,1,4,7,10
Comments