297360

Appears in sequences

• G.f.: Sum_{n>=0} n^n * x^n * (1 + n*x)^n / (1 + n*x + n^2*x^2)^(n+1).at n=7A240921
• Number of inefficient arrangements in A373182, where inefficient means that the maximum number of persons that a seating arrangement can hold is not achieved.at n=15A373829
• a(n) = n! - 2(n-1)! + 3(n-2)!.at n=7A374649