A365650 - OEIS

%I #11 Nov 04 2023 18:24:35

%S 1,4,36,660,16687

%N Number of free n-polyominoids, allowing both corner- and edge-connections.

%C These structures could be called polypletoids (or pseudo-polyominoids), because they are related to polyplets (polyominoids) as polyominoids (pseudo-polyominoes) are related to polyominoes.

%H Pontus von Brömssen, <a href="/A365650/a365650.svg">Illustration for sizes 1..3</a>.

%H <a href="/index/Pol#polyominoes">Index entries for sequences related to polyominoes</a>.

%Y Cf. A000105 (polyominoes), A030222 (polyplets), A075679 (polyominoids), A365651 (fixed), A365652 (corner-connections only).

%Y 30th row of A366766.

%K nonn,hard,more

%O 1,2

%A _Pontus von Brömssen_, Sep 17 2023