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 symmetric after a rotation by 180 degrees.

A123815

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 symmetric after a rotation by 180 degrees.

Terms

    a(0) =1a(1) =37a(2) =73a(3) =2995a(4) =9235a(5) =404559a(6) =1360441

External references