login

Year-end appeal: Please make a donation to the OEIS Foundation to support ongoing development and maintenance of the OEIS. We are now in our 61st year, we have over 378,000 sequences, and we’ve reached 11,000 citations (which often say “discovered thanks to the OEIS”).

Maximum number of ways in which a set of integer-sided rectangular pieces can tile an n X 3 rectangle, up to rotations and reflections.
4

%I #5 Mar 11 2023 08:38:24

%S 1,5,8,95,682,4801,33807

%N Maximum number of ways in which a set of integer-sided rectangular pieces can tile an n X 3 rectangle, up to rotations and reflections.

%e The following table shows the sets of pieces that give the maximum number of tilings for n <= 7. The solutions are unique except for n = 1 and n = 3.

%e \ Number of pieces of size

%e n \ 1 X 1 | 1 X 2 | 1 X 3

%e ---+-------+-------+------

%e 1 | 3 | 0 | 0

%e 1 | 1 | 1 | 0

%e 1 | 0 | 0 | 1

%e 2 | 2 | 2 | 0

%e 3 | 3 | 3 | 0

%e 3 | 2 | 2 | 1

%e 4 | 3 | 3 | 1

%e 5 | 4 | 4 | 1

%e 6 | 7 | 4 | 1

%e 7 | 8 | 5 | 1

%e It seems that all optimal solutions for A361219 are also optimal here, but for n = 1 and n = 3 there are other optimal solutions.

%Y Third column of A361221.

%Y Cf. A361219, A360632.

%K nonn,more

%O 1,2

%A _Pontus von Brömssen_, Mar 05 2023