A212808 Irregular triangle read by rows: row n gives number of cycles of length k in map on Catalan family of size n.
1, 1, 1, 1, 2, 0, 1, 5, 0, 1, 1, 14, 0, 1, 0, 0, 0, 2, 42, 0, 2, 3, 0, 1, 4, 132, 0, 2, 0, 0, 0, 14, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 0, 0, 0, 1, 429, 0, 2, 7, 0, 0, 28, 0, 0, 1, 1, 0, 0, 0, 0, 1, 0, 0, 0, 0, 2, 0, 0, 0, 1
Offset: 0
Examples
Triangle begins 1 1 1 1 2 0 1 5 0 1 1 14 0 1 0 0 0 2 42 0 2 3 0 1 4 132 0 2 0 0 0 14 0 0 0 0 0 0 0 0 0 0 0 0 0 1 0 0 0 1 429 0 2 7 0 0 28 0 0 1 1 0 0 0 0 1 0 0 0 0 2 0 0 0 1 ... ...
Links
- Robert Donaghey, Automorphisms on Catalan trees and bracketing, J. Combin. Theory, Series B, 29 (1980), 75-90.
Formula
T(n,0) = A000108(n).
T(n,0) = sum_{k>0} k*T(n,k) (see Donaghey, paragraph before (13)).
Comments