A023418 Denominator of n*(n-3)*(3*n^2-6*n+2)/(3*(n-1)*(n-2)).

1, 9, 18, 5, 45, 63, 28, 54, 135, 55, 198, 117, 91, 315, 360, 68, 459, 513, 190, 315, 693, 253, 828, 450, 325, 1053, 1134, 203, 1305, 1395, 496, 792, 1683, 595, 1890, 999, 703, 2223, 2340, 410, 2583, 2709