30185domain: NAppears in sequencesMaximal troughs in decimal expansions of Pi: positions of troughs equal to 8.at n=31A105276Number of binary sequences of length n that contain at least one contiguous subsequence 011.at n=15A232580G.f. A(x) satisfies: A(x) = 1 / (1 + x - 2 * x * A(-4*x)).at n=4A349046