A group is indecomposable if it cannot be expressed as a non-trivial direct product. The trivial group is excluded by convention.
Inverse Euler transform of A000679.
Table of n, a(n) for n=0..10.
a(n) = A090751(2^n).
For n = 3, the a(3) = 3 indecomposable groups of order 2^3 = 8 are cyclic, dihedral and quaternion (C_8, D_8, Q_8)
Sequence in context: A001120 A117722 A024419 * A094448 A063805 A125046
Adjacent sequences: A186514 A186515 A186516 * A186518 A186519 A186520
Nick Krempel, Feb 22 2011