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A367557
The number of fixed kissing polyominoes with n cells.
1
4, 40, 260, 1428, 7184, 34238, 157398, 705518, 3104394, 13469766, 57811669, 245990766
OFFSET
7,1
COMMENTS
Translations are allowed, but not rotations or reflections.
A polyomino is 'kissing' if there exist two cells that touch only at a corner such that no cell exists touching both edgewise simultaneously.
First thirteen terms calculated by filtering the output of Redelmeier's Algorithm.
LINKS
Alain Goupil, Marie-Eve Pellerin, and Jérôme de Wouters d'Oplinter, Partially Directed Snake Polyominoes, Discrete Applied Mathematics, Volume 236, 2018.
EXAMPLE
The smallest kissing polyomino has area 7; its four rotations determine the first term in the sequence:
OOO
O O
OO
CROSSREFS
Sequence in context: A270088 A115286 A119635 * A283660 A215701 A366667
KEYWORD
nonn,hard,more
AUTHOR
Johann Peters, Nov 22 2023
EXTENSIONS
a(14)-a(18) from John Mason, Sep 25 2024
STATUS
approved