OFFSET
0,4
EXAMPLE
The a(3) = 3 matrices are:
[1, 1, 0] [1, 1, 1] [1, 1, 1]
[1, 0, 1] [1, 1, 0] [1, 1, 0]
[1, 0, 0] [1, 0, 1] [1, 0, 1]
[0, 1, 1] [0, 1, 0] [0, 1, 1]
[0, 1, 0] [0, 0, 1]
[0, 0, 1]
CROSSREFS
KEYWORD
nonn,more
AUTHOR
Andrew Howroyd, Feb 02 2020
STATUS
approved