OFFSET
1,4
COMMENTS
This was originally based on the data in Jinyuan Wang's A324042, and then extended by Lars Blomberg.
It would be nice to have a formula for these entries. It is easy to see that the first column is 2n-3 for n>1.
LINKS
Lars Blomberg, Table of n, a(n) for n = 1..3240 (the first 80 rows)
Lars Blomberg, Scott R. Shannon and N. J. A. Sloane, Graphical Enumeration and Stained Glass Windows, 1: Rectangular Grids, (2021). Also arXiv:2009.07918.
EXAMPLE
Triangle begins:
0,
1, 1,
3, 8, 3,
5, 12, 12, 5,
7, 22, 32, 22, 7,
9, 28, 40, 40, 28, 9,
11, 38, 58, 74, 58, 38, 11,
...
CROSSREFS
KEYWORD
nonn,tabl
AUTHOR
N. J. A. Sloane, Mar 20 2020
EXTENSIONS
a(29) and beyond from Lars Blomberg, Apr 23 2020
STATUS
approved