313912domain: NAppears in sequencesa(n) = Sum_{k=0..6} binomial(n,k).at n=26A008859a(n) = Sum_{k=0..n-3} T(n,k) * T(n,k+3), with T given by A026300.at n=5A026942Numbers of vectors with 2*n integers such that each element is either 1 or -1, and their sum > n.at n=12A226197a(n) = Sum_{k=0..n} binomial(4*n+2,k).at n=6A387009