Number of ways, counted up to symmetry, to build a contiguous building with n LEGO blocks of size 1 X 3 which is flat, i.e., with all blocks in parallel position.
A123772
Number of ways, counted up to symmetry, to build a contiguous building with n LEGO blocks of size 1 X 3 which is flat, i.e., with all blocks in parallel position.
Terms
- a(0) =1a(1) =3a(2) =17a(3) =107a(4) =761a(5) =5607a(6) =42730a(7) =331851a(8) =2618024a(9) =20895964a(10) =168398683a(11) =1367838390a(12) =11184711448a(13) =91976811135
External references
- oeis: A123772