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A073148
Triangle of numbers {a(n,k), n >= 0, 0<=k<=n} defined by a(0,0)=1, a(n,0)=A006013(n), a(n+1,n)=A001764(n+1), a(n,m) = Sum A001764(n-k)*a(n,k), k=0..m.
0
1, 2, 3, 7, 9, 12, 30, 37, 43, 55, 143, 173, 194, 218, 273, 728, 871, 961, 1045, 1155, 1428, 3876, 4604, 5033, 5393, 5778, 6324, 7752, 21318, 25194, 27378, 29094, 30744, 32655, 35511, 43263, 120175
OFFSET
0,2
COMMENTS
Compare to A073147. Related to generalized Catalan numbers; in particular, C(3n,n)/(2n+1) (enumerates ternary trees and also non-crossing trees)(A001764).
These numbers are cardinalities of some intervals in the Tamari lattices. - F. Chapoton, Jul 15 2021
FORMULA
a(n, m) = Sum A001764(n-k)*a(n, k), k=0..m.
EXAMPLE
{1}, {2,3}, {7,9,12}, {30,37,43,55}, {143,173,194,218,273},{728,871,961,1045,1155,1428}, {3876,4604,5033,5393,5778,6324,7752}, ...
CROSSREFS
KEYWORD
easy,nonn,tabl
AUTHOR
Paul D. Hanna, Jul 18 2002
STATUS
approved