A377946
Cogrowth sequence of the 16-element group C2^2:C4 = .
1, 1, 2, 10, 40, 136, 512, 2080, 8320, 32896, 131072, 524800, 2099200, 8390656, 33554432, 134225920, 536903680, 2147516416, 8589934592, 34359869440, 137439477760, 549756338176, 2199023255552, 8796095119360, 35184380477440, 140737496743936, 562949953421312
Offset: 0
Formula
G.f.: (12*x^4-14*x^3+8*x^2-5*x+1) / ((4*x-1) * (2*x-1) * (4*x^2+1)).
Comments