6062080domain: NAppears in sequencesMaximum of the absolute values of the coefficients of P(n,x) where P(n,x) = 4^(n-1)*Product_{k=0..n} (x - cos(k*Pi/n)^2).at n=9A076625Consider the Post tag system defined in A284116; a(n) = number of binary words of length n which terminate in a cycle.at n=22A289671