478150656domain: NAppears in sequencesa(n) is the number of occurrences of 11s in the palindromic compositions of m=2*n-1 = the number of occurrences of 12s in the palindromic compositions of m=2*n.at n=23A079863Number of horizontal plane Brown's diagonal Latin squares of order 2n with the first row in order.at n=4A379145