Number of nonisomorphic ways a loop can cross a road (running East-West) 2n times.
A077460
Number of nonisomorphic ways a loop can cross a road (running East-West) 2n times.
Terms
- a(0) =1a(1) =1a(2) =1a(3) =3a(4) =12a(5) =70a(6) =464a(7) =3482a(8) =27779a(9) =233556a(10) =2038484a(11) =18357672a(12) =169599492a(13) =1601270562a(14) =15401735750a(15) =150547249932
External references
- oeis: A077460