OFFSET
1,4
COMMENTS
Equivalently, there is an edge between two nodes if the corresponding n-celled polyominoes can be obtained from the same (n-1)-celled polyomino by adding one cell.
FORMULA
a(n) <= A098891(n).
CROSSREFS
KEYWORD
nonn,more
AUTHOR
Pontus von Brömssen, Nov 18 2023
STATUS
approved