311808

Appears in sequences

• Number of edges in the n-Menger sponge graph.at n=3A291066
• Triangle read by rows: T(n,k) is the number of permutations of k elements from [1..n] with longest consecutive chain size less than 3.at n=53A340106
• a(n) = 2^(n-3)*(3*binomial(n,4) + 4*binomial(n,2) + 8).at n=11A383868