9829820

Appears in sequences

• a(n) = Sum_{k=0..floor(n/2)} C(n-k,k)*C(n-k,k+1)/(n-k) * a(k), with a(0)=1.at n=19A118928
• Number of permutations of [n] with every alternating run of length less than 3 in which the last alternating run has length 2.at n=12A246014
• Number of permutations of n letters that have all valleys even and all peaks odd and that end with an ascent.at n=12A246015