260887834350domain: NAppears in sequencesa(n) = binomial(n^2, n).at n=9A014062Binomial coefficients C(n,72).at n=9A017736Binomial coefficients C(81,n).at n=9A017797Triangle read by rows: T(n,k) = binomial(k*n,n), 1 <= k <= n.at n=44A096130a(n) = binomial(9*n, n).at n=9A169958