Number of ways, counted up to symmetry, to build a contiguous building with n LEGO blocks of size 1 X 4 which is flat, i.e., with all blocks in parallel position.

A123780

Number of ways, counted up to symmetry, to build a contiguous building with n LEGO blocks of size 1 X 4 which is flat, i.e., with all blocks in parallel position.

Terms

    a(0) =1a(1) =4a(2) =33a(3) =294a(4) =2951a(5) =30668a(6) =328999a(7) =3596934a(8) =39932206a(9) =448517488a(10) =5086259884a(11) =58135266335

External references