65708

Appears in sequences

• Number of ways to build a contiguous building with n LEGO blocks of size 1 X 6 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.at n=9A123801
• G.f. satisfies: A(x) = x + (1-x)*A(A(x))^2.at n=7A220379
• Number of blunt polytans (polyaboloes) with n cells, identifying mirror images. A blunt polytan is one with no acute corners.at n=15A305606
• G.f. A(x) satisfies A(x) = (1 + x)/(1 - x*A(x))^3.at n=6A379171