248724domain: NAppears in sequencesCentral coefficients of triangle A185384.at n=5A208473Triangular array read by rows. T(n,k) is the number of 2 tuple lists of length n that have exactly k coincidences; n >= 0, 0 <= k <= n.at n=30A2267804*(n + 7)^3 - 27*(n + 7)^2 = (4*n +1)*(n+7)^2.at n=35A245033