54658domain: NAppears in sequencesNumber of length 4 1..(n+2) arrays with no leading or trailing partial sum equal to a prime.at n=23A254207Number of unordered n-tuples {x_1, x_2, x_3, ..., x_n} such that Sum_{k=1..n} 1/x_k is an integer and x_k is an integer between 1 and n for 1 <= k <= n.at n=16A349148