Number of intransitive (or alternating, or Stanley) trees: vertices are [0,n] and for no i<j<k are both (i,j) and (j,k) edges.

A007889

Number of intransitive (or alternating, or Stanley) trees: vertices are [0,n] and for no i<j<k are both (i,j) and (j,k) edges.

Terms

    a(0) =1a(1) =1a(2) =2a(3) =7a(4) =36a(5) =246a(6) =2104a(7) =21652a(8) =260720a(9) =3598120a(10) =56010096a(11) =971055240a(12) =18558391936a(13) =387665694976

External references