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 A032165 Number of aperiodic necklaces of n beads of 10 colors. 3
 10, 45, 330, 2475, 19998, 166485, 1428570, 12498750, 111111000, 999989991, 9090909090, 83333249175, 769230769230, 7142856428565, 66666666659934, 624999993750000, 5882352941176470, 55555555499944500 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,1 LINKS Vincenzo Librandi, Table of n, a(n) for n = 1..500 C. G. Bower, Transforms (2) Y. Puri and T. Ward, Arithmetic and growth of periodic orbits, J. Integer Seqs., Vol. 4 (2001), #01.2.1. F. Ruskey, Necklaces, Lyndon words, De Bruijn sequences, etc. [Cached copy, with permission, pdf format only] FORMULA "CHK" (necklace, identity, unlabeled) transform of 10, 0, 0, 0... a(n) = Sum_{d|n} mu(d)*10^(n/d)/n. MATHEMATICA f[d_]:=MoebiusMu[d] 10^(n/d)/n; a[n_]:=Total[f/@Divisors[n]]; a[0]=1; Table[a[n], {n, 1, 20}] (* Vincenzo Librandi, Oct 14 2017 *) PROG (PARI) a(n) = sumdiv(n, d, moebius(d)*10^(n/d))/n; \\ Andrew Howroyd, Oct 13 2017 CROSSREFS Column 10 of A074650. Sequence in context: A278641 A219709 A061772 * A124174 A264414 A188699 Adjacent sequences:  A032162 A032163 A032164 * A032166 A032167 A032168 KEYWORD nonn AUTHOR STATUS approved

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Last modified December 12 16:06 EST 2018. Contains 318077 sequences. (Running on oeis4.)