84616

Appears in sequences

• G.f.: (1 - 7*x - sqrt(49*x^2 - 18*x + 1))/(2*x).at n=5A082366
• a(n) = 11 + floor((2 + Sum_{j=1..n-1} a(j))/3).at n=31A120156
• Number of ordered pairs (p,q) of permutations of [n] with equal up-down signatures and p(1)=1 if n>0.at n=7A262233
• Sum of the even parts in the partitions of n into 9 parts.at n=41A309659