%I #14 Sep 16 2018 09:56:20
%S 1,5,9,51,131,807,2129,13967,39701,265152,781478,5287858,16094282,
%T 110147280,342365511,2360643691
%N Number of ways to build a contiguous building with n LEGO blocks of size 1 X 8 on top of a fixed block of the same size so that the building is flat, i.e., with all blocks in parallel position and symmetric after a rotation by 180 degrees.
%C The base block is not counted among the n and must be the only block in the bottom layer of the building.
%H <a href="/wiki/Index_to_OEIS:_Section_Lc#LEGO">Index entry for sequences related to LEGO blocks</a>
%Y Cf. A112389, A123762 - A123827, A123829 - A123849.
%K nonn
%O 1,2
%A _Søren Eilers_, Oct 29 2006
%E a(11)-a(16) from _Søren Eilers_, Sep 16 2018