Number of ways, counted up to symmetry, to build a contiguous building with n LEGO blocks of size 1 X 7 which is flat, i.e., with all blocks in parallel position, and symmetric after a rotation by 180 degrees.
A123805
Number of ways, counted up to symmetry, to build a contiguous building with n LEGO blocks of size 1 X 7 which is flat, i.e., with all blocks in parallel position, and symmetric after a rotation by 180 degrees.
Terms
- a(0) =1a(1) =1a(2) =7a(3) =10a(4) =100a(5) =160a(6) =1688a(7) =2853a(8) =30903a(9) =53721a(10) =592395a(11) =1053025a(12) =11711448a(13) =21151575a(14) =236789391a(15) =432872895
External references
- oeis: A123805