40999516domain: NAppears in sequencesa(n) = Sum_{k=0..n} C(n*(n+1)/2,k).at n=8A066383Numbers of vectors with 2*n integers such that each element is either 1 or -1, and their sum > n.at n=17A226197a(n) = Sum_{k=0..n} binomial(4*n+4,k).at n=8A387011