Number of general plane trees whose n-th subtree from the left is equal to the n-th subtree from the right, for all its subtrees (i.e., are palindromic in the shallow sense).
A073192
Number of general plane trees whose n-th subtree from the left is equal to the n-th subtree from the right, for all its subtrees (i.e., are palindromic in the shallow sense).
Terms
- a(0) =1a(1) =1a(2) =2a(3) =3a(4) =8a(5) =18a(6) =54a(7) =155a(8) =500a(9) =1614a(10) =5456a(11) =18630a(12) =64960a(13) =228740a(14) =814914a(15) =2926323a(16) =10589916a(17) =38561814a(18) =141219432a(19) =519711666a(20) =1921142832a(21) =7129756188a(22) =26555149404a(23) =99228108222a(24) =371886574632
External references
- oeis: A073192