479682domain: NAppears in sequencesTriangle read by rows, 3^k*S_3(n, k) where S_m(n, k) are the Stirling-Frobenius subset numbers of order m; n >= 0, k >= 0.at n=33A225466a(n) = 1944*n^2 - 5016*n + 3138 (n >= 1).at n=16A304838