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A032198 "CIK" (necklace, indistinct, unlabeled) transform of 1,2,3,4... 2
1, 3, 6, 13, 25, 58, 121, 283, 646, 1527, 3601, 8678, 20881, 50823, 124054, 304573, 750121, 1855098, 4600201, 11442085, 28527446, 71292603, 178526881, 447919418, 1125750145, 2833906683, 7144450566, 18036423973 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,2

LINKS

Table of n, a(n) for n=1..28.

Index entries for sequences related to necklaces

C. G. Bower, Transforms (2)

P. Flajolet and M. Soria, The Cycle Construction In SIAM J. Discr. Math., vol. 4 (1), 1991, pp. 58-60.

FORMULA

1/n*Sum_{d divides n} phi(n/d)*A004146(d). - Vladeta Jovovic, Feb 15 2003

PROG

(PARI)

N = 66;  x = 'x + O('x^N);

f(x)=sum(n=1, N, n*x^n );

gf = sum(n=1, N, eulerphi(n)/n*log(1/(1-f(x^n)))  );

v = Vec(gf)

/* Joerg Arndt, Jan 21 2013 */

CROSSREFS

Cf. A032170.

Equals A005594(n)-1.

Sequence in context: A215984 A074890 A244704 * A079941 A019300 A072762

Adjacent sequences:  A032195 A032196 A032197 * A032199 A032200 A032201

KEYWORD

nonn

AUTHOR

Christian G. Bower

STATUS

approved

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Last modified November 26 03:51 EST 2014. Contains 250017 sequences.