OFFSET
0,2
COMMENTS
The condition that the rows be in nonincreasing order is equivalent to considering nonequivalent matrices up to permutation of rows.
LINKS
Andrew Howroyd, Table of n, a(n) for n = 0..100
FORMULA
a(n) = Sum_{k=0..n} Stirling1(n,k)*A322487(k).
EXAMPLE
The a(2) = 28 matrices include 6 with 2 rows, 10 with 3 rows, 8 with 4 rows, 3 with 5 rows and 1 with 6 rows. The 16 with 2 or 3 rows are:
[3 2] [3 1] [3 0] [2 3] [2 1] [2 0] [3 1] [3 0]
[0 1] [0 2] [0 3] [1 0] [1 2] [1 3] [0 1] [0 2]
[0 1] [0 1]
.
[2 2] [2 1] [2 1] [2 0] [2 0] [2 0] [1 3] [1 2]
[1 0] [1 1] [1 0] [1 2] [1 1] [1 0] [1 0] [1 1]
[0 1] [0 1] [0 2] [0 1] [0 2] [0 3] [1 0] [1 0]
CROSSREFS
KEYWORD
nonn
AUTHOR
Andrew Howroyd, Jan 11 2020
STATUS
approved