183586707648domain: NAppears in sequencesa(n) = Sum_{k=0..2n-3} T(n,k) * T(n,k+3), with T given by A026519.at n=13A027265a(n) = Sum_{k=0..2n-3} T(n,k) * T(n,k+3), with T given by A026536.at n=14A027270