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 A160957 a(n) = Sum_{d|n} Moebius(n/d)*d^(b-1)/phi(n) for b = 11. 2
 1, 1023, 29524, 523776, 2441406, 30203052, 47079208, 268173312, 581120892, 2497558338, 2593742460, 15463962624, 11488207654, 48162029784, 72080070744, 137304735744, 125999618778, 594486672516, 340614792100, 1278749869056 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,2 COMMENTS a(n) is the number of lattices L in Z^10 such that the quotient group Z^10 / L is C_n. - Álvar Ibeas, Nov 26 2015 REFERENCES J. H. Kwak and J. Lee, Enumeration of graph coverings, surface branched coverings and related group theory, in Combinatorial and Computational Mathematics (Pohang, 2000), ed. S. Hong et al., World Scientific, Singapore 2001, pp. 97-161. See p. 134. LINKS Álvar Ibeas, Table of n, a(n) for n = 1..10000 FORMULA a(n) = A069095(n)/A000010(n). - R. J. Mathar, Jul 12 2011 From Álvar Ibeas, Nov 26 2015: (Start) Multiplicative with a(p^e) = p^(9e-9) * (p^10-1) / (p-1). For squarefree n, a(n) = A000203(n^9). (End) MATHEMATICA b = 11; Table[Sum[MoebiusMu[n/d] d^(b - 1)/EulerPhi@ n, {d, Divisors@ n}], {n, 20}] (* Michael De Vlieger, Nov 27 2015 *) PROG (PARI) vector(100, n, sumdiv(n^9, d, if(ispower(d, 10), moebius(sqrtnint(d, 10))*sigma(n^9/d), 0))) \\ Altug Alkan, Nov 26 2015 CROSSREFS Sequence in context: A023060 A223079 A011560 * A038997 A068026 A075946 Adjacent sequences:  A160954 A160955 A160956 * A160958 A160959 A160960 KEYWORD nonn,mult AUTHOR N. J. A. Sloane, Nov 19 2009 EXTENSIONS Definition corrected by Enrique Pérez Herrero, Oct 30 2010 STATUS approved

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Last modified August 18 04:17 EDT 2017. Contains 290684 sequences.