56010096

Appears in sequences

• 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.at n=10A007889
• Solution to the Dancing School Problem with 9 girls and n+9 boys: f(9,n).at n=9A079914
• Solution to the Dancing School Problem with n girls and n+9 boys: f(n,9).at n=8A079928