A036728 G.f. satisfies A(x) = 1 + x*cycle_index(G,A(x)) where G = cyclic group of order 7 generated by (1,2,...,7).
1, 1, 1, 4, 15, 62, 274, 1260, 5973, 28975, 143176, 718070, 3645876, 18703560, 96799076, 504797258, 2649947859, 13992164283, 74262871273, 395964705460, 2119994732940, 11392843953996, 61432524907686, 332279234332898, 1802324611950162
Offset: 0