77505domain: NAppears in sequencesNumber of meaningful differential operations of the n-th order on the space R^9.at n=14A090994Number of inversion sequences of length n avoiding the consecutive pattern 001.at n=9A328437a(n) = Sum_{k=0..n} binomial(3*n,k) * binomial(3*n-k-1,n-k).at n=5A370097