356721

Appears in sequences

• a(n) = 3^(-1+floor(n/2))*A(n), where A(n) = 3*A(n-1) + A(n-2) - A(n-3)/3 with A(0)=A(1)=3, A(2)=11.at n=8A217336
• The number of permutations of length n sortable by 2 block interchanges.at n=12A228401