0,9

a(n-1)=number of aperiodic necklaces (Lyndon words) with 7 black beads and n-7 white beads.

D. J. Broadhurst, On the enumeration of irreducible k-fold Euler sums and their roles in knot theory and field theory

Index entries for sequences related to Lyndon words

G.f.: (1+x^3)^2/((1-x)^4(1-x^2)^2(1-x^7)).

Cf. A000031, A001037, A051168. Same as A051172(n+1).

First differences of A011853.

A column of triangle A011847.

Sequence in context: A166213 A004036 A051172 this_sequence A032192 A118425 A097809

Adjacent sequences: A011794 A011795 A011796 this_sequence A011798 A011799 A011800

nonn,easy

N. J. A. Sloane (njas(AT)research.att.com), David Broadhurst (D.Broadhurst(AT)open.ac.uk)