14846262964domain: NAppears in sequencesa(n) = 4^n - binomial(2*n,n).at n=17A068551Number of n X 2 0..1 arrays with row sums equal and column sums unequal to adjacent columns.at n=33A202736Number of n-step random walks on a line starting from the origin and returning to it at least once.at n=34A307768