A229774 T(n,k)=Number of n X n 0..k arrays with rows in lexicographically nondecreasing order and columns in nonincreasing order.
2, 3, 6, 4, 22, 20, 5, 60, 322, 70, 6, 135, 3232, 12958, 252, 7, 266, 21331, 1058494, 2179956, 924, 8, 476, 103222, 35452250, 3062815568, 1976588468, 3432, 9, 792, 397460, 637396928, 843211336888, 90462380211862, 10811999412826, 12870, 10
Offset: 1
Examples
Some solutions for n=3 k=4 ..2..2..0....3..3..3....2..1..1....1..0..0....1..1..0....2..0..0....2..2..2 ..3..0..0....4..0..0....3..0..0....1..3..0....3..0..3....2..2..2....3..3..1 ..4..3..3....4..2..0....3..4..4....2..4..1....4..4..1....2..2..2....4..4..0
Links
- R. H. Hardin, Table of n, a(n) for n = 1..62
Formula
Empirical for row n:
n=1: a(n) = n + 1
n=2: a(n) = (1/6)*n^4 + (5/6)*n^3 + (11/6)*n^2 + (13/6)*n + 1
n=3: [polynomial of degree 9]
n=4: [polynomial of degree 16]
Comments