a(n) is the number of canonical polygons with 2n edges having 2-fold rotational symmetry.
A307454
a(n) is the number of canonical polygons with 2n edges having 2-fold rotational symmetry.
Terms
- a(0) =1a(1) =3a(2) =9a(3) =33a(4) =123a(5) =513a(6) =2077a(7) =8759a(8) =37184a(9) =159508a(10) =688446a(11) =2993451a(12) =13082724
External references
- oeis: A307454