98469domain: NAppears in sequencesa(n) = Sum_{k=0..n-1} T(n,k) * T(n,k+1), with T given by A026300.at n=6A026940The Wiener index of the cyclic phenylene with n hexagons (n>=3).at n=18A224456Expansion of (A(x)^2+A(x^2))/2 where A(x) = A001006(x).at n=13A275207Expansion of (A(x)^2-A(x^2))/2 where A(x) = A001006(x).at n=13A275208