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Number of Catalan objects fixed by three-fold application of the Catalan bijections A057511/A057512 (Deep rotation of general parenthesizations/plane trees).
4

%I #4 Oct 17 2015 08:36:23

%S 1,1,2,3,8,18,43,104,273,702,1870,4985,13562,37038,102266,283774,

%T 793189,2227115,6286044,17811751,50672898,144639235,414181050,

%U 1189365940,3424477813,9883578364,28589660227,82870288432,240672107114

%N Number of Catalan objects fixed by three-fold application of the Catalan bijections A057511/A057512 (Deep rotation of general parenthesizations/plane trees).

%F a(n) = A079216(n, 3)

%p A079224 := n -> A079216bi(n,3);

%Y The third row of A079216. The leftmost edge of the triangle A079219 and also its row sums shifted by one. Occurs in A073202 as row 43639. Cf. A057546, A079223-A079227.

%K nonn

%O 0,3

%A _Antti Karttunen_ Jan 03 2002