64945

Appears in sequences

• The number of 321- and 2143-avoiding permutations of length n.at n=14A088921
• a(0)=1, a(1)=1, a(n) = 9*a(n/2) for even n >= 2, and a(n) = 8*a((n-1)/2) + a((n+1)/2) for odd n >= 3.at n=41A116526