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%I #15 Dec 04 2023 12:32:13
%S 4,24,200,1924,20228,225788,2631672
%N Number of fixed (4,3)-polyominoids with n cells, allowing right-angled (or hard) connections only.
%C Two cubes sharing a face have a right-angled connection if they do not lie in the same 3-dimensional affine subspace.
%C Connections that are not right-angled (flat connections) may occur, but the polyominoids considered here must be connected through right-angled connections only.
%C Also, number of fixed polysticks in 4 dimensions with right-angled connections.
%H Wikipedia, <a href="https://en.wikipedia.org/wiki/Polyominoid">Polyominoid</a>.
%H <a href="/index/Pol#polyominoes">Index entries for sequences related to polyominoes</a>.
%Y Cf. A075678, A365655, A366337, A366339, A366340 (free).
%Y 41st and 77th row of A366767.
%K nonn,hard,more
%O 1,1
%A _Pontus von Brömssen_, Oct 07 2023