Number of nonisomorphic ways a loop can cross a road (running East-West) 2n times.
A078591
Number of nonisomorphic ways a loop can cross a road (running East-West) 2n times.
Terms
- a(0) =1a(1) =1a(2) =1a(3) =4a(4) =21a(5) =131a(6) =914a(7) =6910a(8) =55477a(9) =466729a(10) =4076430a(11) =36712325a(12) =339195058a(13) =3202515525a(14) =30803440806a(15) =301094270964
External references
- oeis: A078591