OFFSET

0,3

COMMENTS

The condition that the columns be in decreasing order is equivalent to considering nonequivalent matrices with distinct columns up to permutation of columns.

LINKS

Andrew Howroyd, Table of n, a(n) for n = 0..200

EXAMPLE

The a(2) = 3 matrices are:

[1 1] [1 0] [1 0]

[1 0] [1 1] [0 1]

[0 1] [0 1] [1 1]

CROSSREFS

KEYWORD

nonn

AUTHOR

Andrew Howroyd, Jan 24 2020

STATUS

approved