Number of proper colorings of the 2n-gon with 2 instances of each of n colors under rotational symmetry.
A284664
Number of proper colorings of the 2n-gon with 2 instances of each of n colors under rotational symmetry.
Terms
- a(0) =0a(1) =1a(2) =5a(3) =96a(4) =3528a(5) =199620a(6) =15908400a(7) =1697149440a(8) =233631921600
External references
- oeis: A284664