10381281domain: NAppears in sequencesNumber of walks of length n between two nodes at distance 2 in the cycle graph C_7.at n=24A095307a(n) = Sum_{k=0..floor(n/7)} binomial(n,7*k).at n=26A306852a(n) = Sum_{k=0..n} binomial(2*n,7*k).at n=13A387845